JP4659503B2 - Power generation device and lubricating oil recovery method - Google Patents

Description

  The present invention relates to a power generator that recovers relatively low-temperature exhaust heat and converts the heat energy into electric power, and in particular, lubricating oil used for lubricating a turbine generator bearing serves as a working medium circulation path working medium. The present invention relates to a power generation apparatus and a method for recovering lubricating oil that can be separated from a working medium and collected in a lubricating oil circulation path when mixed.

  Attempts have been made to effectively recover relatively low-temperature exhaust heat such as exhaust gas of about 200 ° C. to 400 ° C. or exhaust water of 60 ° C. to 100 ° C. as generated power. Such low-temperature exhaust heat recovery can be realized as a closed system power generation device using Rankine cycle, etc., and in order to make the device compact, a low-boiling working medium is not used as the working medium. It is used.

  Lubrication of a turbine generator bearing in the above-described closed system power generator is usually performed using lubricating oil. The lubricating oil system in which this lubricating oil circulates is normally separated from the working medium system constituting the heat cycle by a labyrinth seal or the like, but cannot be shut off without a gap, and depending on the conditions, the working medium The lubricating oil may leak into the system, or the working medium may enter the lubricating oil system. In particular, when the turbine generator is started or stopped, the lubricating oil and the working medium are likely to be mixed due to the difference in temperature and pressure between the lubricating oil and the working medium. If left as it is, the lubricating oil component is lost even in the lubricating oil system, the working medium becomes the main component, the viscosity decreases, and the bearing lubrication may be hindered. To prevent this, the working medium mixed in the lubricating oil is stored in the tank, separated by the difference in specific gravity between the lubricating oil and the working medium, and an attempt is made to return the lubricating oil to the lubricating oil system and the working medium to the working medium system. It has also been made.

  The method of separating due to the difference in specific gravity between the lubricating oil and the working medium has a certain effect for discharging the working medium in the lubricating oil, but depending on the conditions, the separation of the lubricating oil and the working medium becomes insufficient, Lubricating oil may be mixed into the separated working medium, or conversely, lubricating oil may be mixed into the working medium system. When the lubricating oil is mixed in the working medium, the heat transfer characteristics of the working medium are deteriorated, and the steam pressure is lowered due to the rise in boiling point. In addition, the reduction of the lubricating oil may cause poor circulation of the lubrication system.

  In addition, when the difference between the pressure of the lubrication system and the internal pressure of the condenser is small, the height of the lubricating oil tank is increased to return the separated working medium and the liquid head is increased, or auxiliary power such as a pump is used. Means are needed. In addition to the lubricating oil mixed in the separated working medium, there are places where the lubricating oil may be mixed in the working medium in the apparatus, and a means for collecting the lubricating oil is desired.

  The present invention has been made in view of the above points, and has a power generation system including a lubricating oil recovery means that separates and recovers lubricating oil separated from the lubricating oil system and mixed in the working medium of the working medium system and returns it to the lubricating oil system. An object of the present invention is to provide an apparatus and a method for recovering lubricating oil.

In order to achieve the above object, an invention according to claim 1 comprises a steam generator, a condenser, an expander, a working medium circulation path through which the working medium circulates, and a generator driven by the expander. Then, the working medium vapor generated by the heat from the external heat source in the steam generator is guided to the expander, the generator is driven, and the working medium vapor from the expander is guided to the condenser to be supplied from the outside. Condensed by a cooling medium, the condensed working medium liquid is sent to the steam generator by a working medium circulation pump, and a lubricating oil circulation path and a lubricating oil supply pump provided in the lubricating oil circulation path are provided. A power generator configured to feed lubricating oil to a bearing that supports a rotor shaft of the expander and / or the generator by the lubricating oil supply pump;
A gas-liquid separator that separates the working medium vapor and the working medium liquid is provided, and the gas-liquid separator is connected to the lubricating oil circulation path through a flow rate control unit, and the working medium vapor from the steam generator is supplied to the gas generator. The lubricating oil introduced to the liquid separator and returned to the lubricating oil circulation path via the flow rate control means is returned to the lubricating oil circulation path through which the working medium near the liquid level of the working medium liquid separated by the gas-liquid separator is mixed. The working medium liquid separated by the separator is configured to return to the working medium circulation path.

  According to a second aspect of the present invention, in the power generation apparatus according to the first aspect, an oil-liquid separator that separates the lubricating oil and the working medium liquid by a specific gravity difference is provided between the gas-liquid separator and the flow rate control means. The lubricating oil mixed with the working medium near the liquid level of the working liquid separated by the gas-liquid separator is guided to the oil-liquid separator, and the lubricating oil separated by the oil-liquid separator is supplied to the flow rate control means. And returning to the lubricating oil circulation path, and the separated working medium liquid is returned to the working medium circulation path.

  According to a third aspect of the present invention, in the power generation apparatus according to the second aspect, the oil-liquid separator includes an oil-liquid separation cylinder that separates the lubricating oil and the working medium liquid due to a specific gravity difference, and the gas-liquid separator. A pipe for guiding the lubricating oil mixed with the working medium near the liquid level of the separated working medium liquid to the oil-liquid separating cylinder is provided.

  According to a fourth aspect of the present invention, in the power generation device according to the second aspect, the oil-liquid separator includes an oil-liquid separation space surrounded by an oil-liquid separation weir at an inner bottom portion of the gas-liquid separator. The working medium liquid separated by the gas-liquid separator is guided to the oil-liquid separating space through the working medium discharge port provided in the oil-liquid separating weir, and the working medium liquid separated by the gas-liquid separator The lubricating oil mixed with the working medium near the surface is guided to the oil-liquid separation space through the oil-liquid separation weir, and the lubricating oil separated by the specific gravity difference in the oil-liquid separation space is returned to the lubricating oil circulation path. The separated working medium liquid is returned to the working medium circulation path.

  According to a fifth aspect of the present invention, in the power generation device according to any one of the first to fourth aspects, the working medium steam generated by the steam generator is designed to be substantially superheated steam. Features.

  According to a sixth aspect of the present invention, in the power generation device according to any one of the first to fifth aspects, the working medium circulation amount that limits the amount of the working medium supplied from the working medium circulation path to the steam generator. A control means is provided, and when collecting the lubricating oil, the amount of the working medium supplied to the steam generator is limited, and the working medium steam discharged from the steam generator is superheated steam. And

  According to a seventh aspect of the present invention, in the power generation apparatus according to any one of the first to sixth aspects, a superheat degree detecting means for detecting a superheat degree of the working medium vapor is provided at an outlet of the steam generator, When the temperature decreases, the amount of working medium sent to the steam generator is reduced, and when the degree of superheat increases, the amount of working medium fed is controlled to increase. The working medium circulation amount control means is provided.

  According to an eighth aspect of the present invention, in the power generation apparatus according to any one of the first to seventh aspects, the lubricating oil containing the working medium is exposed to an atmosphere under reduced pressure in the lubricating oil circulation path. An oil regenerator for evaporating water is provided.

  According to the ninth aspect of the present invention, the working medium vapor generated by the heat from the external heat source in the steam generator is guided to the expander, the generator is driven, and the working medium vapor from the expander is transmitted in the condenser. Condensed by an external cooling medium, the condensed working medium liquid is sent to a steam generator by an operating circulation pump, and lubricating oil is applied to a bearing that supports the rotor shaft of the expander or the generator. In the lubricating oil recovery method for recovering the lubricating oil mixed in the working medium of the power generation device having a lubricating oil circulation path for circulating the oil, the working medium vapor from the steam generator is guided to the gas-liquid separator, The lubricating oil mixed with the working medium near the liquid level of the working medium liquid separated by the separator is returned to the lubricating oil circulation path.

A tenth aspect of the present invention is the lubricating oil recovery method according to the ninth aspect, wherein the lubricating oil mixed with the working medium near the working medium liquid surface in the gas-liquid separator is mixed with the lubricating oil and the working medium liquid. It leads to the oil-liquid separator which isolate | separates with a specific gravity difference, The lubricating oil isolate | separated by this oil-liquid separator is returned to the said lubricating oil circulation path, It is characterized by the above-mentioned.

  According to the first aspect of the present invention, the working medium vapor from the steam generator is guided to the gas-liquid separator, and the working medium in the vicinity of the liquid level of the working medium liquid separated by the gas-liquid separator is mixed. Since the oil is returned to the lubricating oil circulation path via the flow rate control means, the lubricating oil mixed in the working medium circulation path can be efficiently collected in the lubricating oil circulation path.

  According to the second to fourth aspects of the present invention, the mixture of the lubricating oil and the working medium near the liquid surface of the working medium liquid separated by the gas-liquid separator is led to the oil-liquid separator, and the oil-liquid separator Since the lubricating oil separated in (1) is returned to the lubricating oil circulation path via the flow rate control means, the lubricating oil mixed in the working medium circulation path can be more efficiently recovered in the lubricating oil circulation path.

  According to the fifth to seventh aspects of the present invention, since the working medium vapor generated by the steam generator is designed to be substantially superheated steam, most of the liquid separated by the gas-liquid separator is lubricated. The lubricating oil that has become oil and mixed into the working medium circulation path can be more efficiently recovered in the lubricating oil circulation path.

  According to the eighth aspect of the present invention, since the oil regenerator for evaporating the working medium by exposing the lubricating oil containing the working medium to the lubricating oil circulation path in an atmosphere under reduced pressure is provided. The working medium can be vaporized and separated to return to the working medium circulation path, and this is recovered even when the working medium is accompanied by the lubricating oil or when the working medium is mixed in the lubricating oil for other reasons. be able to.

  According to the ninth and tenth aspects of the present invention, the mixture of the lubricating oil and the working medium near the liquid surface of the working medium liquid separated by the gas-liquid separator is returned to the lubricating oil circulation path. Lubricating oil mixed in can be efficiently collected in the lubricating oil circulation path.

  According to the tenth aspect of the present invention, the mixture of the lubricating oil and the working medium in the vicinity of the liquid level of the working medium in the gas-liquid separator is led to the oil-liquid separator, and the separated lubricating oil is supplied to the lubricating oil circulation path. Therefore, the lubricating oil mixed in the working medium circulation path can be more efficiently recovered in the lubricating oil circulation path.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic system configuration of a power generator according to the present invention. This power generation device is a power generation device of a closed system, and is a power generation device using a Rankine cycle. This power generator recovers exhaust heat from an external exhaust heat source (for example, exhaust gas at about 200 ° C. to 400 ° C. or exhaust hot water at 60 ° C. to 100 ° C.) 101 and generates a high-pressure steam 102 as a working medium. 11, a turbine (expander) 13 driven by expanding the high-pressure steam 102, a turbine generator 14 including a generator 12 driven by the turbine 13, and low-pressure steam after driving the turbine 13 103 is cooled by an external cooling medium (for example, cooling water) 104 to form a condensate 105 of the working medium, and the condensate 105 of the working medium condensed by the condenser 15 is pressurized. A liquid feed pump 16 for feeding into the steam generator 11 is provided, and these are connected to the steam generator 11, the turbine 13, the condenser 15, and the liquid feed pump 16 through a working medium circulation path 17.

  In addition, although this embodiment demonstrates the example which uses the turbine 13 of the turbine generator 14 as an expander, the expander which drives the generator 12 is not restricted to the turbine 13, A screw type expander and a scroll type expander. The same applies to other types of expanders.

Here, for example, HFC123 or trifluoroethanol (CF ₃ CH ₂ OH), which is a low boiling point medium, is used as the working medium. By using a heat source such as exhaust gas having a relatively low temperature (approximately 200 ° C. to 400 ° C.) or exhaust water having a relatively low temperature (60 ° C. to 100 ° C.), the heat is first converted into high-pressure steam as a working medium. Thus, the turbine 13 directly connected to the generator 12 of the turbine generator 14 can be rotationally driven to generate power. The working medium is not limited to a low boiling point medium, and may be a high boiling point medium.

  In the power generation apparatus, the liquid supply pump 16 feeds the condensate 105 of the working medium to the steam generator 11. The condensate 105 receives the heat energy of the external exhaust heat source 101 by the steam generator 11 and evaporates to a high pressure steam 102. The high-pressure steam 102 of the working medium is sent to the turbine 13 directly connected to the generator 12 of the turbine generator 14, where the turbine 13 is driven by the expansion of the high-pressure steam 102 to drive (rotate) the generator 12 to generate power. To do. The low-pressure steam 103 discharged from the turbine 13 is cooled by a condenser 15 by a cooling medium 104 such as cooling water or outside air, condensed, and cooled by a supercooler (not shown) as necessary, and sent to a liquid. It is sucked by the pump 16 and goes around the closed system.

  The main shaft of the turbine generator 14 is supported by bearings 18 and 19. The bearings 18 and 19 are pressurized with the lubricating oil 106 stored in the lubricating oil tank 21 by the lubricating oil supply pump 20 and supplied to the bearings 18 and 19 through the lubricating oil circulation path 24. The lubricating oil 106 that lubricates and cools the bearings 18 and 19 is heated, heated, stored in the lubricating oil trays 22 and 23, and returned to the lubricating oil tank 21 through the lubricating oil circulation path 24. A labyrinth seal LS is provided between the generator 12 and the turbine 13. A lubricant filter 27 for removing dust, a flow meter 28 for confirming the flow of the lubricant, and the like are provided on the discharge port side of the lubricant supply pump 20 in the lubricant circulation path 24. Further, the inside of the lubricating oil tank 21 and the inside of the condenser 15 are communicated with each other via a control valve 46 by a medium return pipe 33.

  A temperature regulator (apparatus) 25 is arranged in the discharge side piping (lubricant circulation path 24) of the lubricant supply pump 20, and is operated by the liquid feed pump 16 as a cooling medium in the temperature regulator (apparatus) 25. The medium condensate 105 is supplied through the cooling medium pipe 26, and the high-pressure steam 102 from the steam generator 11 is supplied as the heating medium through the heating medium pipe 40, whereby the temperature of the lubricating oil 106 supplied to the bearings 18 and 19 is increased. The desired range is maintained. A device (thermometer or the like) for measuring the temperature of the lubricating oil is provided between the temperature controller (device) 25 and the bearing, and when the temperature of the lubricating oil rises above a certain value, it is provided in the heating medium pipe 40. When the opening of the control valve 41 is adjusted in the closing direction and the temperature of the lubricating oil falls below a certain value, the opening of the control valve 42 of the cooling medium pipe 26 is adjusted in the closing direction. It can be adjusted. Here, the position where a device (thermometer or the like) for measuring the temperature of the lubricating oil is provided is preferably between the temperature regulator (device) 25 and the bearing, but may be between the bearing and the lubricating oil tank 21. . The working medium supplied to the temperature controller (device) 25 is returned to the condenser 15 through the medium return pipe 30. The medium return pipe 30 is provided with an orifice 31 for controlling the flow rate.

  In this power generator, a lubricating oil tank 21 is provided in a lubricating oil circulation path 24 for supplying lubricating oil to the bearings 18 and 19 of the turbine generator 14, and the oil formed integrally in the lubricating oil tank 21 is provided. A regenerator 60 is provided, and an oil droplet separator 70 formed integrally therewith is provided. By providing the oil regenerator 60, the working medium mixed in the lubricating oil can be vaporized and the working medium in the lubricating oil 106 can be separated by bringing the lubricating oil 106 into contact with the gas phase under reduced pressure. .

  FIG. 2 is a diagram showing the structure of an oil regenerator 60 and an oil droplet separator 70 that are integrally formed in the lubricating oil tank 21 of the power generation apparatus. In the oil regenerator 60, a plurality of (eight in the figure) evaporating dishes 61 are horizontally and alternately arranged with a predetermined gap in the vertical direction. The lubricating oil heated by cooling and lubricating the bearings 18 and 19 of the turbine generator 14 is guided to the oil regenerator 60 through the lubricating oil circulation path (pipe) 24. The oil regenerator 60 is supplied to the uppermost evaporating dish 61, flows into the lower evaporating dish 61 in contact with the gas phase, and stays at the bottom of the lubricating oil tank 21 from the lowermost evaporating dish 61. As the lubricating oil 106 flows over the evaporating dish 61 and comes into contact with the gas phase, the working medium contained in the lubricating oil 106 is vaporized and separated. In order to vaporize the working medium in the lubricating oil, it is desirable that the temperature of the lubricating oil be higher and the pressure in the oil regenerator 60 be lower.

  In the lubricating oil circulation system, the temperature becomes highest immediately after the bearing is cooled. Therefore, the oil regenerator 60 is preferably provided in a portion where the lubricating oil returns from the bearings 18 and 19, and further, the oil regeneration is performed. It is desirable to communicate the condenser 60 with the condenser 15. Here, the condenser 15 and the lubricating oil tank 21 are communicated with each other through a medium vapor return pipe 33. Further, the above-described temperature controller 25 keeps the oil temperature within a desired range. In this power generation apparatus, the vaporized working medium is returned to the condenser 15 through an oil droplet separator 70 formed integrally with the oil regenerator 60. The oil droplet separator 70 has a structure in which a plurality of (three in the figure) baffle plates 71 are horizontally and alternately arranged with a predetermined gap in the upper part of the lubricating oil tank 21.

  In this power generation device, a gas-liquid separator 34 is provided at the outlet of the steam generator 11, and an oil-liquid separator 37 is provided in the gas-liquid separator 34. In general, the steam generator 11 is known to improve heat transfer by flowing about 5 to 20% more working medium than the amount of working medium to be evaporated, and collects surplus working medium liquid. In many cases, a gas-liquid separator 34 is provided for the purpose of circulating back to the inlet of the steam generator 11 through the medium recirculation pipe 39. The gas-liquid separator 34 necessary for the power generation apparatus may also be used as this gas-liquid separator. Although the gas-liquid separator of this example is an adhesive type, other types of gas-liquid separators may be used.

  Since the lubricating oil mixed in the working medium sent to the steam generator 11 circulating through the medium recirculation pipe 39 is not vaporized even when heated by the steam generator 11, the working liquid vapor is used in the gas-liquid separator 34. And is returned to the inlet of the steam generator 11 through the medium recirculation pipe 39. Therefore, during normal operation, the lubricating oil mixed in the working medium is collected in the steam generator 11, and the concentration of the lubricating oil is the highest when the operation is separated from the working medium vapor by the gas-liquid separator 34. It becomes a medium liquid. For example, it is possible to recover the lubricating oil mixed in the working medium circulation path 17 by returning a part of the working medium liquid separated by the gas-liquid separator 34 to the lubricating oil circulation path 24. However, in this case, the working fluid is mixed in the lubricating oil circulation path 24 more than necessary, which is not always preferable.

  As described above, since the concentration of the lubricating oil in the working medium is relatively high in the gas-liquid separator 34, the lubricating oil is likely to deposit on the working medium liquid surface. Therefore, in this power generation device, the oil-liquid separator 37 is connected to the gas-liquid separator 34, and the lubricating oil collected near the liquid surface is returned to the oil regenerator 60 of the lubricating oil tank 21 through the lubricating oil return pipe 38. I decided to collect it.

  FIG. 3 is a diagram showing the structure of the gas-liquid separator 34 and the oil-liquid separator 37 of the power generation apparatus. As shown in the drawing, the oil / liquid separator 37 rises from the vicinity of the liquid surface of the working medium liquid 107 of the gas / liquid separator 34 and the oil / liquid separator 37 to separate the lubricating oil and the working medium. Lubricated oil recovery pipe 37b, working medium return pipe 37c for returning the separated working medium liquid 107 to the working medium circulation path 17 (medium recirculation pipe 39), and lubricating oil 106 of the oil-liquid separating cylinder 37a gather. A lubricating oil return pipe 38 for taking out the lubricating oil from the portion through the flow rate control means (orifice 29 (see FIG. 1)). Reference numeral 34a denotes a droplet pressure-sensitive adhesive plate disposed vertically on the gas-liquid separator 34.

  The liquid level in the gas-liquid separator 34 is considered to be substantially constant unless the operating conditions fluctuate so much, but here, the liquid level in the gas-liquid separator 34 is detected by the liquid level detector LV. The feed amount of the working medium to the steam generator 11 is controlled so that the liquid level becomes substantially constant. Instead of this, the liquid level in the gas-liquid separator 34 may be kept constant by a siphon tube or the like. Instead of the liquid level in the gas-liquid separator 34, the operation in the oil-liquid separation cylinder 37a is performed. The interface between the medium and the lubricating oil may be detected.

  As shown in FIG. 3, in the lubricating oil return pipe 38 of the oil-liquid separator 37, an orifice 29 is provided in the pipe as a flow control means (see FIG. 1), and this is connected to the oil regenerator 60 of the lubricating oil tank 21. is doing. During operation of the power generation device, the gas-liquid separator 34 has a high pressure and the oil regenerator 60 has a low pressure, so that the lubricating oil 106 in the oil-liquid separator 37 is sucked out from the lubricating oil return pipe 38. At this time, since the working medium vapor in the oil-liquid separator 37 is also sucked out, the oil-liquid separator 37 has a slightly lower pressure than the gas-liquid separator 34. Therefore, the lubricating oil 106 deposited near the liquid surface is sucked out from the gas-liquid separator 34 to the oil-liquid separator 37 together with the working medium liquid 107 and the working medium vapor. The sucked working medium vapor is sucked into the lubricating oil return pipe 38 together with the lubricating oil 106 staying in the oil-liquid separator 37.

  On the other hand, the working medium liquid 107 and the lubricating oil 106 are separated in the oil liquid separating cylinder 37a, and the working medium liquid 107 stays downward and the lubricating oil 106 stays upward. Here, the working medium liquid 107 separated in the gas-liquid separator 34 is circulated to the working medium circulation path 17 through the medium recirculation pipe 39. In this power generation device, the working medium liquid 107 is returned to the working medium circulation path 17 by returning the working medium liquid 107 from the gas-liquid separator 34 to the inlet of the steam generator 11. Here, in order to return the working medium liquid 107 in the oil-liquid separator 37 to the medium recirculation pipe 39, the pressure of the working medium in the medium recirculation pipe 39 needs to be slightly lower than in the gas-liquid separator 34. is there. For this reason, the present power generation apparatus is illustrated as having an orifice, but this is extremely small as the pressure loss, so even if the orifice is not particularly provided, only the pressure loss of the pipe is sufficient. As shown in FIG. 7, the working medium liquid 107 of the gas-liquid separator 34 is once guided to the oil-liquid separator 37, and then the working medium liquid 107 from which the lubricating oil has been removed by the oil-liquid separator 37 is used. It does not matter even if it returns to the steam generator 11 via the medium recirculation piping 39.

  Further, as shown in FIG. 4, the oil / liquid separator 37 may be configured integrally in the gas / liquid separator 34. In the oil-liquid separator shown in FIG. 4, an oil-separating weir 37 d having a working medium discharge port 37 f is provided in the gas-liquid separator 34. The working medium separated by the gas-liquid separator 34 is guided from the working medium discharge port 37f to the oil-liquid separation space 34c, and is discharged from the gas-liquid separator 34 through the medium recirculation pipe 39. Since the flow rate of the working medium liquid 107 is substantially proportional to the difference between the surface of the working medium liquid 107 of the gas-liquid separator 34 and the surface of the lubricating oil 106 of the oil-liquid separator 37, it may be considered to be always constant. . A drip-proof plate 34b is provided above the oil-liquid separation space 34c.

  Here, as in the case of FIG. 3, the liquid level in the gas-liquid separator 34 is detected by the liquid level detector LV, and steam is generated so that the liquid level does not fall below the upper edge of the oil separation weir 37d. The feed amount of the working medium to the container 11 is controlled. Instead of the liquid level in the gas-liquid separator 34, the interface between the working medium 107 and the lubricating oil 106 in the oil-liquid separation space 34c may be detected.

  When the amount of the working medium liquid 107 separated by the gas-liquid separator 34 exceeds this amount, the working medium liquid 107 that has exceeded exceeds the oil separation weir 37d and flows into the oil-liquid separation space 34c. At this time, the deposited lubricating oil near the liquid level of the working medium liquid 107 of the gas-liquid separator 34 flows into the oil-liquid separation space 34 c together with the working medium liquid 107. In the oil-liquid separation space 34c, the lubricating oil 106 is accumulated upward due to the difference in specific gravity, as in the case of the oil-liquid separating cylinder 37a in FIG. 3, and the lubricating oil is recovered by extracting it through the lubricating oil return pipe 38. In FIG. 1, 43 is a control valve provided in the lubricating oil circulation path 24, 45 is a control valve provided in the pressure equalizing pipe 44 that communicates the inside of the lubricating oil tank 21 and the turbine generator 14, and 35 is the condenser 15. A liquid level gauge provided at 41, 41 is a control valve provided at the heating medium pipe 40, and 42 is a control valve.

  In either of the oil-liquid separators 37 shown in FIGS. 3 and 4, in this power generation device, the lubricating oil is regenerated in the lubricating oil tank 21 through the lubricating oil return pipe 38 and the internal pressure thereof is substantially equal to the internal pressure of the condenser 15. To the vessel 60. Thereby, the working medium contained in the recovered lubricating oil can be quickly separated by the oil regenerator 60. The lubricating oil return pipe 38 is provided with an orifice 29. Thereby, the return of the lubricating oil is adjusted, but instead, the return amount of the lubricating oil may be controlled by an automatic valve or a manual valve. Further, in this power generation apparatus, the working medium liquid 107 in the gas-liquid separator 34 is returned to the steam generator 11 through the medium recirculation pipe 39, but may be returned to the condenser 15 or the like.

  When returning to the condenser 15, the separated working medium liquid is returned so that the interface between the working medium liquid 107 and the lubricating oil 106 in the oil-liquid separator 37 or the oil-liquid separation space 34c is constant. It is desirable to control the amount. This is because the difference between the inlet pressure of the steam generator 11 and the pressure in the gas-liquid separator 34 is small, whereas the difference in pressure between the gas-liquid separator 34 and the condenser 15 is relatively large. This is because if the amount is not properly controlled, the lubricating oil in the gas-liquid separator 34 and the working medium vapor may be discharged to the condenser 15. Specifically, a control valve is provided in the middle of the pipe for returning the separated working medium liquid 107 to the condenser 15, and the lubricating oil 106 and the working medium liquid 107 are placed in the oil-liquid separator 37 or the oil-liquid separation space 34c. It is preferable to provide a detector for detecting the interface, and to open the control valve when the interface rises and to close when the interface falls. Instead of the oil / liquid separator 37 or the oil / liquid separation space 34c, an interface in the gas / liquid separator 34 may be detected.

  Further, in order to return the working medium mixed in the lubricating oil to the working medium circulation path 17, instead of providing the oil regenerator 60, the working medium mixed in the lubricating oil is collected at the bottom of the lubricating oil tank 21, You may make it isolate | separate and collect | recover. That is, the working medium mixed in the lubricating oil stored in the lubricating oil tank 21 stays in the lower part of the lubricating oil tank 21 due to the specific gravity difference. This may be sent to the condenser 15 and discharged as necessary, or vaporized by a heater or the like, and returned to the condenser 15 or the like as working medium vapor.

  Further, in this power generation device, if the amount of working medium liquid at the outlet of the steam generator 11 is reduced, the effect of separation is enhanced. This can be easily realized by reducing the feed flow rate of the working medium to the steam generator 11, and particularly when it is highly necessary to recover the lubricating oil, reducing the feed amount of the working medium can reduce the amount of lubricating oil. It is also possible to promote separation.

  FIG. 5 is a diagram showing another schematic system configuration of the power generator according to the present invention. In FIG. 5, the parts denoted by the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. The same applies to other drawings. In this power generation device, a lubricating oil return pipe 38 that collects and sends lubricating oil to the oil regenerator 60 from the vicinity of the liquid level of the gas-liquid separator 34 is provided. An oil / liquid separator similar to that shown in FIG. 1 may be provided near the liquid surface of the gas / liquid separator 34. The working medium liquid 107 separated by the gas-liquid separator 34 is returned to the condenser 15 through the working medium return pipe 51, and a control valve 50 is provided in the working medium return pipe 51 to supply the condenser 15 to the condenser 15. The flow rate of the separation liquid can be adjusted. The control valve 50 is controlled so that the liquid level of the working medium liquid 107 is at a fixed position by a detection signal of a liquid level detector 52 provided in the gas-liquid separator 34.

  Further, the liquid feed pump 16 has a variable speed device so that the working medium liquid (condensate 105) to be sent to the steam generator 11 can be freely controlled. Here, the variable speed is realized by making the liquid feed pump 16 driven by alternating current power an inverter drive, but a DC brushless motor having a variable speed function may be used, instead of a variable speed device, A control valve may be provided at the outlet of the liquid feed pump. Further, the working medium liquid 107 of the gas-liquid separator 34 may be returned to the steam generator 11 instead of the condenser 15. Further, the heat of the working medium liquid sent to the condenser 15 is exchanged with the working medium liquid sent from the condenser 15 to the steam generator 11 by the heat recovery unit 49, thereby suppressing the efficiency reduction.

  In this power generation apparatus, when the lubricating oil mixed in the working medium is to be separated, first, the liquid feeding pump 16 is controlled so that the amount of the working medium (condensate 105) to be sent to the steam generator 11 is more than usual. Reduce. Thereby, the working medium at the outlet of the steam generator 11 becomes superheated steam. At this time, the lubricating oil mixed in the working medium is deposited as oil droplets in the superheated steam, but this is collected by the gas-liquid separator 34. Accordingly, the lubricating oil accumulates near the liquid surface of the working medium liquid 107 of the gas-liquid separator 34. The lubricating oil is returned to the lubricating oil circulation path 24 by opening the control valve 36 in the lubricating oil return pipe 38.

  At this time, the amount of the working medium liquid (condensate 105) to be fed is not particularly limited as long as the working medium at the outlet of the steam generator 11 is reduced to such an extent that it becomes superheated steam. In this power generation device, the pressure and temperature of the working medium at the outlet of the steam generator 11 are measured, detected by the temperature detector 53 and the pressure detector 54, and the superheat degree of the working medium vapor is calculated from the detected temperature and the detected pressure. The superheat degree is controlled to be a set value. That is, the amount of working medium liquid sent to the steam generator 11 is increased when the degree of superheat increases, and the amount of feed is decreased when the degree of superheat decreases. The method for calculating the degree of superheating of the working medium vapor is not limited to the above example. For example, by measuring the temperature and the temperature difference between the working medium temperature in the steam generator 11 and the working medium steam, an approximate superheating degree is obtained. The degree can be calculated. It is also possible to roughly “estimate” the difference between the temperature of the external heat source 101 and the working medium vapor temperature.

  Moreover, as conditions for performing this separation operation of the lubricating oil, for example, it is performed when it is determined that the heat transfer of the steam generator 11 has deteriorated, or when the liquid level of the lubricating oil 106 in the lubricating oil tank 21 is lowered. It can be performed when the operating time, the number of activations, etc. reach a specified value, but the following method is effective.

[Method to be performed according to the temperature of exhaust heat supplied to the generator]
The first method is based on the temperature of exhaust heat supplied to the power generator. When the power generation device separates the lubricating oil, generally, the amount of exhaust heat recovery decreases because the amount of the working circulation medium in the steam generator 11 decreases. Therefore, if the amount of exhaust heat supplied from the external exhaust heat source 101 is reduced, it is desirable to balance the two if the operation is performed as described above. Therefore, the above operation may be performed when the supply amount of exhaust heat is measured and the like is lowered. However, the measurement of the exhaust heat amount is performed by a medium (hot water, exhaust gas) that conveys thermal energy from the external exhaust heat source 101. Etc.) It is necessary to measure the flow rate, which is generally expensive. In addition, it may be possible to obtain information on the amount of heat supplied from the external heat source 101 as a current signal, a voltage signal, or numerical information by digital communication, but it may be necessary to unify the information transmission procedure of both, Not easy. In such a case, the simplest means is to use the temperature of the external exhaust heat source 101. Generally, in many exhaust heat sources, when the amount of exhaust heat decreases, the temperature of exhaust heat also decreases. Moreover, it is relatively easy to measure the temperature of exhaust heat. Therefore, when the temperature of exhaust heat is constantly measured and this temperature falls below a predetermined specified value, the recovery of the lubricating oil can be performed without impairing the power generation capacity of the power generation device by entering the recovery operation of the lubricating oil. It becomes possible.

[Method of recovering lubricating oil when the working medium at the outlet of the steam generator becomes superheated steam]
The second is a method of recovering the lubricating oil when the working medium at the outlet of the steam generator 11 becomes superheated steam. As described above, it is desirable to balance the amount of exhaust heat required by the power generation device and the amount of exhaust heat supplied to the power generation device. In particular, when the exhaust heat water that circulates is used as a heat source, if both become imbalanced, the temperature of the external heat exhaust source 101 rises and falls, affecting other devices connected to the same exhaust heat source, Affect the ability. Therefore, when the exhaust heat temperature rises and falls, it can be considered to balance the heat recovery of the power generation device.

  If it is this power generation device, the amount of heat recovery of the power generation device can be controlled relatively freely by adjusting the amount of working medium liquid (condensate) sent to the steam generator 11 by the liquid feed pump 16. Specifically, when the exhaust heat temperature of the external exhaust heat source 101 increases, the amount of exhaust of the working medium is increased to increase the amount of exhaust heat recovery, and when the exhaust heat temperature decreases, the amount of exhaust of the working medium is decreased to reduce the amount of exhaust heat. Reduce recovery. By controlling the heat recovery amount in this way, when the supply amount of the exhaust heat from the external exhaust heat source 101 is small, the feed amount of the working medium liquid is reduced, and the working medium vapor becomes superheated steam. Therefore, in that case, by performing the above-described recovery operation of the lubricating oil, the recovery operation of the lubricating oil can be performed without deteriorating the capability of the power generation device, and the recovery of the lubricating oil can be performed without degrading the capability of the power generation device Is possible.

[Method to be performed while power generation is stopped]
The third method is a method performed while power generation is stopped. This power generator is a power generator using the turbine generator 14. In the power generator using the turbine generator 14, a shutoff valve 47 is provided at the steam inlet of the turbine 13, and a bypass valve 48 is provided in parallel with the turbine generator 14. Is generally provided. When the power generator is to be stopped, for safety, the shut-off valve 47 is first closed to stop the turbine generator 14, and the bypass valve 48 is opened to release the steam in the steam generator 11. At this time, the heat of the steam generator 11 and the heat source medium is radiated without being particularly used. Further, when the turbine generator 14 is to be operated, the working medium begins to circulate with the shut-off valve 47 closed and the bypass valve 48 opened, the pressure of the steam generator 11 increases, and the working medium circulates stably. After that, it is common to open the shutoff valve 47 and start power generation. Again, the exhaust heat during this time is exhausted from the condenser 15 without being used effectively.

  In this power generation device, it is possible to recover the lubricating oil by effectively using the heat that is originally ineffective. That is, with the shut-off valve 47 closed and the bypass valve 48 opened, the rotational speed of the liquid feed pump 16 is controlled so that the outlet steam of the steam generator 11 is superheated steam and the lubricating oil 106 is recovered as described above. it can. Further, as described above, it is particularly easy for the lubricating oil to enter the working medium circulation path 17 when the turbine generator 14 is started and when it is stopped. It is reasonable to separate the lubricating oil when the turbine generator 14 is started or stopped. It is correct.

  By collecting the lubricating oil by the first to third methods, the lubricating oil can be collected without impairing the capacity of the power generation device. Of course, these methods may be combined.

  FIG. 6 is a diagram showing another schematic system configuration of the power generator according to the present invention. This power generation apparatus is a power generation apparatus having a once-through steam generator 11 designed so that the outlet steam of the steam generator 11 is always overheated, and the working medium separation liquid separated by the gas-liquid separator 34. Is connected to the lubricating oil circulation path 24 (here, to the oil regenerator 60 of the lubricating oil tank 21) through an orifice 55 which is a flow rate control means. The flow rate control means may be a simple one such as a narrow tube or an orifice, or a control valve may be used. Here, the orifice 55 is used.

  In the power generation device shown in FIG. 6, the supply amount of the working medium liquid to the steam generator 11 can be controlled so that the outlet steam of the steam generator 11 is always superheated steam, as in the power generation device shown in FIG. desirable. In addition, when the working medium liquid temporarily flows into the gas-liquid separator 34 such as at the time of start-up, the condenser 15 and the lubricating oil circulation path 24 are connected in a switchable manner to condense the flowing working medium liquid. It may be possible to return to the container 15. Specifically, when the superheat degree at the outlet of the steam generator 11 is less than or equal to a set value, the separated liquid in the gas-liquid separator 34 is returned to the condenser 15 and when the temperature rises to a set value or more, the lubricating oil circulation path 24 and There are methods such as connecting.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

It is a figure which shows the schematic system configuration | structure of the electric power generating apparatus which concerns on this invention. It is a figure which shows schematic structure of the lubricating oil tank of the electric power generating apparatus which concerns on this invention, an oil droplet regenerator, and an oil droplet separator. It is a figure which shows the gas-liquid separator and oil-liquid separator schematic structure of the electric power generating apparatus which concerns on this invention. It is a figure which shows the gas-liquid separator and oil-liquid separator schematic structure of the electric power generating apparatus which concerns on this invention. It is a figure which shows the schematic system configuration | structure of the electric power generating apparatus which concerns on this invention. It is a figure which shows the schematic system configuration | structure of the electric power generating apparatus which concerns on this invention. It is a figure which shows the gas-liquid separator and oil-liquid separator schematic structure of the electric power generating apparatus which concerns on this invention.

Explanation of symbols

11 Steam Generator 12 Generator 13 Turbine (Expander)
DESCRIPTION OF SYMBOLS 14 Turbine generator 15 Condenser 16 Liquid feed pump 17 Working medium circulation path 18 Bearing 19 Bearing 20 Lubricating oil supply pump 21 Lubricating oil tank 22 Lubricating oil tray 23 Lubricating oil tray 24 Lubricating oil circulation path 25 Temperature regulator 26 Cooling medium piping 27 Lubricating oil filter 28 Flow meter 29 Orifice 30 Refrigerant return pipe 31 Orifice 33 Medium vapor return pipe 34 Gas-liquid separator 35 Liquid level gauge 36 Control valve 37 Oil-liquid separator 38 Lubricating oil return pipe 39 Medium recirculation pipe 40 Heating medium Piping 41 Control valve 42 Control valve 43 Control valve 44 Equal pressure piping 45 Control valve 46 Control valve 47 Shut-off valve 48 Bypass valve 49 Heat recovery device 50 Control valve 51 Working medium return piping 52 Liquid level detector 53 Temperature detector 54 Pressure detection 55 Orifice 60 Oil regenerator 61 Evaporating dish 70 Oil drop separator 71 Board

Claims (10)

A steam generator, a condenser, an expander, a working medium circulation path through which the working medium circulates, and a generator driven by the expander, are generated by heat from an external heat source in the steam generator The generated working medium vapor is guided to the expander, the generator is driven, the working medium vapor from the expander is guided to the condenser, and condensed with an external cooling medium, and the condensed working medium liquid is operated. The medium circulation pump is configured to feed the steam generator, and includes a lubricating oil circulation path and a lubricating oil supply pump provided in the lubricating oil circulation path, and the expander and / or the lubricating oil supply pump. In the power generation device configured to send lubricating oil to a bearing that supports the rotor shaft of the generator,
A gas-liquid separator for separating the working medium vapor and the working medium liquid is provided, and the gas-liquid separator is connected to the lubricating oil circulation path via the flow rate control means ;
The working medium vapor from the steam generator is guided to the gas-liquid separator, and the lubricating oil mixed with the working medium near the liquid surface of the working medium liquid separated by the gas-liquid separator is passed through the flow rate control means. A power generator configured to return to the lubricating oil circulation path and to return the working medium liquid separated by the gas-liquid separator to the working medium circulation path. The power generator according to claim 1,
An oil-liquid separator that separates the lubricating oil and the working medium liquid by a specific gravity difference is provided between the gas-liquid separator and the flow rate control means,
The lubricating oil mixed with the working medium near the liquid level of the working medium liquid separated by the gas-liquid separator is guided to the oil-liquid separator, and the lubricating oil separated by the oil-liquid separator is supplied to the flow control means. And returning the working medium fluid separated by the oil / liquid separator to the working medium circulation path. The power generator according to claim 2,
The oil / liquid separator includes an oil / liquid separation cylinder that separates the lubricating oil and the working medium liquid by a specific gravity difference;
A power generator comprising: a pipe for guiding lubricating oil mixed with a working medium near a liquid surface of the separated working medium liquid in the gas-liquid separator to the oil-liquid separating cylinder. The power generator according to claim 2,
The oil-liquid separator has an oil-liquid separation space surrounded by an oil-liquid separation weir at the inner bottom of the gas-liquid separator, and a working medium discharge port provided in the oil-liquid separation weir in the oil-liquid separation space Through which the separated working medium liquid of the gas-liquid separator is guided through the oil-liquid separating weir, and the lubricating oil mixed with the working medium near the liquid surface of the working medium liquid separated by the gas-liquid separator passes through the oil-liquid separating weir. The structure is such that the lubricating oil guided to the oil-liquid separation space and separated by the specific gravity difference in the oil-liquid separation space is returned to the lubricating oil circulation path, and the separated working medium liquid is returned to the working medium circulation path. A power generator characterized by the above. In the electric power generating apparatus of any one of Claims 1 thru | or 4,
The working medium steam generated by the steam generator is designed to be almost superheated steam. The power generator according to any one of claims 1 to 5,
A working medium circulation amount control means for limiting the amount of working medium supplied to the steam generator from the working medium circulation path is provided, and when the lubricating oil is to be recovered, the working medium supplied to the steam generator A power generator characterized in that the amount of the working medium vapor is limited to a superheated steam discharged from the steam generator. The power generator according to any one of claims 1 to 6,
A superheat degree detecting means for detecting the superheat degree of the working medium steam is provided at the outlet of the steam generator, and when the superheat degree is lowered, the amount of the working medium fed to the steam generator is reduced, and the superheat degree is raised. And a working medium circulation amount control means for controlling the circulation amount of the working medium in the working medium circulation path so as to increase the feed amount of the working medium. The power generator according to any one of claims 1 to 7,
An electric power generator characterized in that an oil regenerator for evaporating the working medium by exposing the lubricating oil containing the working medium to an atmosphere under reduced pressure is provided in the lubricating oil circulation path. The steam generator generates the working medium vapor generated by the heat from the external heat source to the expander, drives the generator, and condenses the working medium vapor from the expander with the external cooling medium in the condenser. The condensed working medium liquid is sent to the steam generator by the working circulation pump, and has a lubricating oil circulation path for circulating the lubricating oil to a bearing that supports the rotor shaft of the expander or the generator. In the lubricating oil recovery method for recovering the lubricating oil mixed in the working medium of the power generation device,
The working medium vapor from the steam generator is guided to the gas-liquid separator, and the lubricating oil mixed with the working medium near the liquid surface of the working medium liquid separated by the gas-liquid separator is returned to the lubricating oil circulation path. A lubricating oil recovery method characterized by the above. The lubricating oil recovery method according to claim 9,
The lubricating oil mixed with the working medium near the working medium liquid level in the gas-liquid separator is led to an oil / liquid separator that separates the lubricating oil and the working medium liquid by a specific gravity difference, and separated by the oil / liquid separator. A method for recovering a lubricating oil, wherein the lubricating oil is returned to the lubricating oil circulation path.

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