JP2010048450A - Leaked steam heat recovery structure from steam motor shaft seal part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recover heat of leaked steam from a shaft seal part of a screw-type steam motor. <P>SOLUTION: The screw-type steam motor 4 generating power by using steam from a boiler 2 drives an oil lubricated type air compressor 5. A heat exchanger 23 and an ejector 35 are provided in a make-up water passage 8 to a water feed tank 7 of the boiler 2. In the heat exchanger 23, indirect heat exchange is performed between lubricating oil and compressed air in the compressor 5 and make-up water to the water feed tank 7. In the ejector 35, water is sprayed from a nozzle 36 to a diffuser 37, and leaked steam from the shaft seal part of the steam motor 4 is sucked to the make-up water passage 8 via a leaked steam passage 39. Thus, the leaked steam is mixed with the make-up water to the water feed tank 7, to promote preheating of water supply to the boiler 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure for effectively using leaked steam from a shaft seal portion of a screw type steam motor. In particular, the present invention relates to a leakage steam heat recovery structure for preheating water supply to a boiler using leakage steam from a shaft seal portion of a screw type steam motor.

In Patent Document 1 below, an air compressor (2) is driven by a screw expander (1), and when the load of the air compressor (2) varies, the steam flowing into the screw expander (1) is controlled. (10) is controlled and responded, and by controlling the bypass valve (9) provided between the steam inflow side and the steam outflow side of the screw expander (1), A method of keeping the back pressure of steam on the outflow side constant is disclosed. Here, the bypass valve (9) is controlled by detecting the back pressure of the steam outlet pipe (5) from the screw expander (1) by the detector (20). The control of the adjusting valve (10) is performed by detecting the rotational speed of the drive shaft of the screw expander (1) with the detector (23).
JP-A-63-45403 (Claims, page 2, page 2, upper right column, line 15-lower left column, line 5, drawing)

  A screw-type steam motor (screw-type expander) is generally configured such that screw rotors that mesh with each other are rotatably held in a hollow casing. Then, the screw rotor is rotated by the steam introduced into the casing and outputs rotational power. The screw rotors rotate in conjunction with each other via a timing gear. The shaft seal is maintained while leaking. Therefore, a non-contact seal such as a labyrinth seal or a visco seal is used for the shaft seal.

  Thus, the screw type steam motor is operated while leaking steam from the shaft seal. Conventionally, this leaked steam is simply exhausted to the atmosphere, which is a waste of energy. Therefore, the problem to be solved by the present invention is to effectively utilize the heat of the leaked steam from the shaft seal portion of the screw type steam motor. At this time, the screw-type steam motor needs to leak the steam from the shaft seal portion during operation as described above, and therefore it is preferable to take care not to inhibit the leakage of the steam. That is, if the back pressure of the non-contact seal is increased, there is a risk of mixing the lubricating oil and steam and the shaft seal portion being damaged.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is directed to the heat leaked from steam leaked from a shaft seal portion of a screw steam motor that generates power using steam. Is a steam heat recovery structure leaking from the shaft seal portion of the steam motor.

  According to the first aspect of the present invention, it is possible to effectively use the leaked steam from the shaft seal portion of the screw-type steam motor to improve the thermal efficiency of the steam utilization system.

  The invention according to claim 2 supplies steam leaking from the shaft seal portion of the steam motor into the stored water of the water supply tank to the boiler. The steam motor shaft seal portion according to claim 1 This is a heat recovery structure for leaking steam from

  According to invention of Claim 2, the water supply to a boiler can be pre-heated by supplying the leakage steam from the shaft seal part of a screw type steam motor to the water supply tank to a boiler.

  The invention according to claim 3 is provided with an indirect heat exchanger in a water supply tank to the boiler or a replenishment water channel to the water supply tank, and through the leaked steam from the shaft seal portion of the steam motor through the indirect heat exchanger, The leak steam heat recovery structure from a steam motor shaft seal according to claim 1, wherein water in the water supply tank or water in the makeup water channel is heated.

  According to the invention described in claim 3, water supply to the boiler is performed by indirect heat exchange between the steam leaked from the shaft seal portion of the screw-type steam motor and the water stored in the water supply tank or the makeup water supplied to the water supply tank. Can be preheated.

  Invention of Claim 4 supplies the leakage steam from the shaft seal part of the said steam motor in the replenishment water path to the water supply tank of a boiler, The steam motor shaft seal part of Claim 1 characterized by the above-mentioned. This is a heat recovery structure for leaking steam from

  According to the fourth aspect of the present invention, the leakage steam path from the shaft seal portion is connected to the supply water path to the boiler. Thereby, leaking steam can be smoothly introduced into the water flow in the make-up water channel, and the water supply to the boiler can be preheated. By the way, when the leaked steam is directly collected in the water supply tank, the steam is blown up. Accordingly, the heat recovery rate is lowered by that amount. On the other hand, according to the invention described in claim 4, the leaked steam from the shaft seal portion is mixed in the supply water path to the water supply tank. Thereby, the amount of steam escaping into the atmosphere is reduced, and as a result, the heat recovery rate can be improved. In addition, since the supply water channel to the boiler and the leakage steam channel from the shaft seal are shared at least in part, the configuration can be simplified and the cost can be reduced.

  According to a fifth aspect of the present invention, an ejector is provided in the middle of the replenishing water channel, water is passed through the replenishing water channel, and the ejector causes leakage steam from the shaft seal portion of the steam motor to enter the replenishing water channel. The steam heat recovery structure leaking from the steam motor shaft seal according to claim 4, wherein the steam is sucked.

  According to the fifth aspect of the present invention, the ejector is installed at the junction of the replenishment water channel to the boiler and the leakage steam channel from the shaft seal, and the leakage water is replenished by the ejector by passing water through the replenishment water channel. Can be drawn into the waterway. Thereby, leaking steam can be introduced more smoothly into the water flow in the make-up water channel, and the water supply to the boiler can be preheated.

  According to a sixth aspect of the present invention, the leakage steam passage that supplies the leakage steam from the shaft seal portion of the steam motor to the makeup water passage is opened to the atmosphere when the pressure in the leakage steam passage becomes equal to or higher than a set value. The steam heat recovery structure for leaking steam from the shaft seal portion of the steam motor according to claim 4 or 5.

  According to the sixth aspect of the present invention, when the pressure in the leakage steam path increases, the leakage of the steam from the shaft seal portion is not inhibited by exhausting the leakage steam to the atmosphere. Therefore, even if the water flow in the make-up water channel is made intermittently or the water flow amount in the make-up water channel changes, the mixing of the lubricating oil and steam is prevented and the shaft seal portion is prevented from being damaged. Preheating water can be preheated.

  According to a seventh aspect of the present invention, a pump is provided in a leakage steam path for supplying leakage steam from the shaft seal portion of the steam motor to the makeup water path, and the leakage steam is discharged into the makeup water path, or The leak steam heat recovery structure from the steam motor shaft seal according to claim 4, wherein a pump is provided in the middle to suck the leaked steam into the makeup water channel.

  According to invention of Claim 7, the leak of the vapor | steam from a shaft seal part is not inhibited by providing a pump in a leakage steam channel or a supplementary water channel. Therefore, even if the water flow in the make-up water channel is made intermittently or the water flow amount in the make-up water channel changes, the mixing of the lubricating oil and steam is prevented and the shaft seal portion is prevented from being damaged. Preheating water can be preheated.

  Further, in the invention according to claim 8, the water in the replenishing water channel is cooled after cooling compressed air and / or lubricating oil as a fluid to be cooled from an oil lubricated compressor driven by the steam motor. The steam leaked from the steam motor shaft seal according to any one of claims 3 to 7, wherein the steam vapor is heated by the steam leaked from the shaft seal of the steam motor and supplied to the water supply tank. It is a recovery structure.

  According to the eighth aspect of the present invention, the cooling of the compressed air and / or lubricating oil as the fluid to be cooled from the compressor driven by the steam motor and the heat from the leaked steam from the shaft seal portion of the steam motor. Recovery can be performed efficiently.

  According to the leak steam heat recovery structure from the shaft seal portion of the present invention, the heat of the leak steam from the shaft seal portion of the screw type steam motor can be effectively used. Typically, the steam supplied from the shaft seal portion of the steam motor can be used to preheat water supplied to the boiler.

  Hereinafter, the leakage steam heat recovery structure from the shaft seal portion of the steam motor according to the present invention will be described in more detail based on examples.

  FIG. 1 is a schematic view showing an example of a steam utilization system to which Embodiment 1 of the leaked steam heat recovery structure of the present invention is applied. In this steam utilization system 1, the leaked steam heat recovery structure 3 of the present invention is applied to preheat water supplied to the boiler 2. Therefore, first, the outline of the steam utilization system 1 will be described, and then the leaked steam heat recovery structure 3 of the present embodiment will be described.

  A steam utilization system 1 shown in FIG. 1 includes a boiler 2, a steam motor 4 that generates power using steam from the boiler 2, and a compressor 5 that is driven by the steam motor 4. The steam motor 4 and the compressor 5 may be configured as one unit 6 as indicated by a two-dot chain line in FIG.

  If the boiler 2 is a steam boiler, the structure in particular will not be ask | required. The boiler 2 is supplied with water from the water supply tank 7. Since the replenishing water channel 8 to the water supply tank 7 is provided with a soft water device (not shown), soft water from which hardness components such as calcium ions and magnesium ions contained in the raw water are removed is supplied to the boiler. In addition to the soft water device, a deoxygenation device (not shown) may be provided. In this case, the degassed soft water is supplied to the boiler 2. By the way, the water supply tank 7 is provided with an overflow path 9 for overflowing a predetermined amount of water to the outside.

  The water supplied to the boiler 2 is vaporized by the boiler 2. The steam from the boiler 2 is supplied to the first steam header 10, and the steam in the first steam header 10 is supplied to one or a plurality of various steam utilizing devices.

  There is a steam motor 4 as one of the steam utilization devices of this type. The steam of the first steam header 10 is supplied to the steam motor 4 through the steam supply path 11. A steam supply valve 12 is provided in the steam supply path 11 from the first steam header 10 to the steam motor 4. By adjusting the opening / closing or opening of the steam supply valve 12, the presence or absence of the steam motor 4 or the output can be adjusted.

  The steam motor 4 is a device that obtains a rotational driving force by the supplied steam. In the steam motor 4, the steam is expanded and decompressed. Therefore, the steam motor 4 functions not only as a drive source for the compressor 5 but also as a pressure reducing valve. Thereby, the steam after being used in the steam motor 4 can be used as it is in various steam utilizing devices (not shown) as the steam after passing through the pressure reducing valve. For this purpose, the steam used by the steam motor 4 is supplied to the second steam header 14 via the exhaust steam passage 13, and the steam of the second steam header 14 is supplied to one or a plurality of various steam utilizing devices. Supplied. The exhaust steam path 13 is provided with a check valve 15 that prevents the backflow of steam to the steam motor 4.

  The first steam header 10 and the second steam header 14 are also connected via the bypass 16. In the present embodiment, the steam supply path 11 from the first steam header 10 to the steam supply valve 12 and the exhaust steam path 13 from the check valve 15 to the second steam header 14 are connected by a bypass path 16. The bypass passage 16 is provided with a bypass valve 17. The bypass valve 17 is preferably a self-powered pressure reducing valve, and its opening degree is mechanically adjusted by itself so as to maintain the steam pressure in the second steam header 14 at a predetermined level. If such a bypass path 16 is provided, the steam can be stably supplied to the steam utilization device of the second steam header 14. For example, even when the steam supply valve 12 is closed and the steam motor 4 is stopped, the steam can be supplied to the steam using device of the second steam header 14 via the bypass 16.

  The steam motor 4 is a screw-type steam motor. FIG. 2 is a schematic view showing a shaft seal portion of the screw-type steam motor 4, and a part thereof is shown in cross section. The screw type steam motor 4 is configured by providing screw rotors 19 and 19 in a hollow casing 18 so as to mesh with each other. Steam is introduced between the screw rotors 19 and 19, and the screw rotor 19 is rotated. Rotational power is output by the rotation of the screw rotor 19. During this time, the steam passes through the steam motor 4 and is expanded and decompressed.

  The screw rotors 19 and 19 rotate together through a timing gear (not shown). In order to prevent the lubricating oil of the timing gear from mixing with the steam, normally, a steam outlet 21 is provided between the rotor body 20 and the timing gear. The steam motor 4 is operated while leaking to the outside. Therefore, a non-contact seal 22 such as a labyrinth seal or a visco seal is used for the shaft seal portion of the screw rotor 19.

  The compressor 5 is not particularly limited as long as it is oil-lubricated, but is a screw-type air compressor here. The screw compressor 5 is a device that sucks gas between screw rotors (not shown) that rotate while meshing with each other, and compresses and discharges the gas by rotation of the screw rotor. In this case, lubricating oil is present in the casing in order to lubricate the screw rotors that rotate in mesh with each other in the casing and to form a space for generating compressed air. This lubricating oil also serves to cool the compression heat generated in the compressor 5 by being water-cooled to a desired temperature. Usually, not only the lubricating oil but also the compressed air obtained is water-cooled.

  The compressor 5 is driven by the steam motor 4. Specifically, the screw rotor of the screw compressor 5 is rotated using the rotational driving force of the screw rotor 19 of the screw steam motor 4. As described above, the compressor 5 is driven by the steam motor 4, but it is preferable that the electric motor 43 (FIGS. 3 to 6) can also be auxiliary driven.

  The lubricating oil and compressed air of the compressor 5 can be cooled by makeup water supplied to the water supply tank 7. In other words, the makeup water to the water supply tank 7 can be heated by the compression heat of the compressor 5. For this purpose, a heat exchanger 23 is provided in the supply water channel 8 to the water supply tank 7. The heat exchanger 23 is normally configured as a part of the unit 6 (more specifically, a part of the compressor 5), as indicated by a two-dot chain line in FIG.

  The heat exchanger 23 passes makeup water to the water supply tank 7, while passing lubricating oil and compressed air of the compressor 5 to be cooled by indirect heat exchange with this water. Therefore, the heat exchanger 23 of the present embodiment includes an oil cooling unit 24 and an air cooling unit 25. Further, makeup water to the feed water tank 7 is passed through the makeup water channel 8 by the heat exchange water pump 26, and the air cooling unit 25 and the oil cooling unit 24 of the heat exchanger 23 provided in the middle of the makeup water channel 8 are sequentially supplied. And supplied to the water supply tank 7.

  The oil cooling section 24 of the heat exchanger 23 is supplied with makeup water to the water supply tank 7, while the lubricating oil of the compressor 5 is passed through indirect heat exchange with this water for cooling. Specifically, the oil cooling unit 24 of the heat exchanger 23 is supplied with lubricating oil from the compressor 5 through the oil supply passage 27, and the lubricating oil is returned to the compressor 5 through the oil discharge passage 28. In this way, the lubricating oil is circulated between the compressor 5 and the heat exchanger 23. At this time, the circulation of the lubricating oil is naturally performed by an internal pressure of an oil separator (not shown) of the compressor 5 or the like, but may be forcibly performed by providing a circulation pump in the oil supply passage 27 in some cases.

  Water supplied to the water supply tank 7 is passed through the air cooling unit 25 of the heat exchanger 23, while compressed air from the compressor 5 is passed through indirect heat exchange with the water for cooling. Specifically, the air cooling unit 25 of the heat exchanger 23 is supplied with compressed air from the compressor 5 via an air supply path 29, and the air is supplied to an air dryer (not shown) via an exhaust path 30. The In this way, the compressed air from the compressor 5 is cooled by the heat exchanger 23, moisture is removed by the air dryer, and sent to various types of compressed air utilization equipment (not shown).

  Although the amount of water supplied to the heat exchanger 23 is also the amount of water supplied to the water supply tank 7 via the replenishment water channel 8, this water supply amount can be changed by inverter control of the heat exchange water supply pump 26. That is, the heat exchange water supply pump 26 provided in the make-up water channel 8 can control the rotation speed by the inverter, and the amount of water supplied to the heat exchanger 23 is adjusted by changing the rotation speed. In the present embodiment, the amount of water supplied to the heat exchanger 23 is adjusted by inverter-controlling the heat exchange water pump 26 so that the lubricating oil supplied from the compressor 5 to the heat exchanger 23 is maintained at a set temperature. The

  Incidentally, the second steam header 14 is provided with a steam pressure sensor 31 in order to grasp the use load of the steam. The vapor pressure sensor 31 monitors the vapor pressure in the second vapor header 14. Therefore, whether or not there is a steam load can be detected based on whether or not the steam pressure is less than a predetermined value. That is, when the steam is used, the steam pressure in the second steam header 14 is lowered, so that the use load of the steam can be detected depending on whether or not it is less than a predetermined value.

  Compressed air from the compressor 5 passes through a compressed air passage 32 (an air supply passage 29 from the compressor 5 to the heat exchanger 23, an exhaust passage 30 from the heat exchanger 23, and a lower passage therethrough). It can be supplied to one or a plurality of compressed air utilization devices (not shown). The compressed air passage 32 is provided with an air pressure sensor 33 in order to grasp the usage load of the compressed air. The air pressure sensor 33 monitors the air pressure in the compressed air passage 32. Therefore, whether or not there is an air load can be detected based on whether or not the air pressure is less than the set value. That is, when compressed air is used, since the air pressure in the compressed air passage 32 decreases, the use load of the compressed air can be detected based on whether or not it is less than the set value. However, a hollow air tank (not shown) may be provided in the middle of the compressed air passage 32, and an air pressure sensor 33 may be provided in the air tank to detect the use load of the compressed air.

  In the steam utilization system 1 of the present embodiment, the controller 34 monitors the detected pressures of the steam pressure sensor 31 and the air pressure sensor 33, and based on this, the opening / closing or opening of the steam supply valve 12 is determined as described below. Control.

  The controller 34 detects that there is a steam load when the vapor pressure of the vapor pressure sensor 31 is less than a predetermined value, and detects that there is an air load when the air pressure of the air pressure sensor 33 is less than a set value. In this case, the steam supply valve 12 is opened and the steam motor is operated. Thus, the compressor 5 is driven by the steam motor 4, but may be auxiliary driven by an electric motor if desired.

  Further, the controller 34 detects that there is no steam load when the vapor pressure of the vapor pressure sensor 31 is equal to or higher than a predetermined value, and detects that there is no air load when the air pressure of the air pressure sensor 33 is equal to or higher than a set value. When doing so, the steam supply valve 12 is closed and the steam motor 4 is stopped.

  Further, the controller 34 detects that there is a steam load when the vapor pressure of the vapor pressure sensor 31 is less than a predetermined value, and detects that there is no air load when the air pressure of the air pressure sensor 33 is equal to or greater than a set value. When doing so, the steam supply valve 12 is closed and the steam motor 4 is stopped. In this case, steam is supplied via the bypass 16 to the second steam header 14 and thus to the steam using device.

  Further, the controller 34 detects that there is no steam load when the vapor pressure of the vapor pressure sensor 31 is equal to or higher than a predetermined value, and detects that there is an air load when the air pressure of the air pressure sensor 33 is less than the set value. If so, the compressor 5 is driven by an electric motor. At this time, the electric motor may drive the compressor (compressor that can be driven by the steam motor 4) 5 or may drive a compressor (not shown) different from the compressor 5. In the latter case, the compressed air from the compressor driven by the electric motor is supplied to the compressed air utilization device via the compressed air passage 32 or the air tank common to the compressed air from the compressor 5 driven by the steam motor 4. It is possible.

  However, the controller 34 detects that there is no steam load when the vapor pressure of the vapor pressure sensor 31 is equal to or higher than a predetermined value, and detects that there is an air load when the air pressure of the air pressure sensor 33 is less than the set value. In this case, the steam motor 4 may be operated by opening the steam supply valve 12 instead of or in addition to the electric motor. Here, when operating the steam motor 4 instead of the electric motor, the electric motor is not necessarily required.

  In order to prevent hunting of opening / closing of the steam supply valve 12, the “set value” and / or “predetermined value” may of course each set an operation gap (differential). For example, when the set lower limit pressure is reached with the use of compressed air, the steam supply valve 12 is opened, and when the set upper limit pressure is reached, the steam supply valve 12 may be closed. Further, the controller 34 may control the opening degree of the steam supply valve 12 based on the detected pressure of the air pressure sensor 33 so as to maintain the air pressure in the set pressure range.

  Next, the leak steam heat recovery structure 3 from the steam motor shaft seal portion of the present embodiment will be described. As described above, the screw steam motor 4 is operated while leaking steam from the shaft seal portion to the steam outlet 21 (FIG. 2). The leaked steam heat recovery structure 3 of the present embodiment uses this leaked steam to heat water supplied to the boiler 2, more specifically makeup water to the water supply tank 7.

  Specifically, an ejector 35 is provided downstream of the heat exchanger 23 in the replenishment water channel 8 to the water supply tank 7. As is well known, the ejector 35 is provided with a nozzle 36 at one end, a diffuser 37 at the other end, and a fluid suction port 38 in the middle. The suction port 38 of the ejector 35 is connected to the steam exhaust port 21 for the steam leaked from the shaft seal portion of the steam motor 4 through the leak steam path 39.

  With this configuration, when water is passed through the replenishment water channel 8, water is ejected from the nozzle 36 to the diffuser 37, and leaked steam from the shaft seal portion of the steam motor 4 is drawn into the suction port 38. Thereby, the replenishment water channel 8 to the water supply tank 7 is heated by mixing the leaked steam, and the water supply to the boiler 2 can be preheated. By mixing the leaked steam into the makeup water supplied to the water supply tank 7, it is possible to suppress the steam blowing up and to improve the heat recovery rate, compared to the case where the leaked steam is put directly into the water supply tank 7. In addition, since the replenishment water path 8 to the water supply tank 7 and the leak steam path 39 from the shaft seal portion have at least a part of the common piping, the configuration can be simplified and the cost can be reduced. .

  By the way, as described above, the screw type steam motor 4 needs to leak steam from the shaft seal portion during operation as described above, and it is not preferable that the steam leakage is inhibited. If the back pressure of the shaft seal portion (pressure on the outlet side of the steam outlet 21) increases, there is a possibility that the lubricating oil and steam are mixed, or the shaft seal portion is damaged. However, in this embodiment, the leaked steam from the shaft seal portion is sucked into the ejector 35, so that such inconvenience is prevented.

  However, the flow rate of the water supply path 8 is adjusted as the amount of water supplied to the heat exchanger 23 as described above. Therefore, the back pressure of the shaft seal portion may increase depending on the amount of water passing through the replenishment water channel 8. Therefore, as shown in FIG. 1, an atmosphere release path 40 to the outside air is provided in the middle of the leak steam path 39, and the atmosphere release path 40 can be opened and closed by an electromagnetic valve 41. If the pressure in the leaking steam passage 39 becomes higher than the set pressure, the solenoid valve 41 is opened by the pressure switch 42 so that the leaking steam is discharged directly from the atmosphere opening path 40 to the atmosphere. Good. In this case, if the pressure drops, the solenoid valve 41 is closed again by the pressure switch 42.

  FIG. 3 is a schematic view showing Example 2 of the leaked steam heat recovery structure 3 of the present invention. The leakage steam heat recovery structure 3 of the second embodiment and the steam utilization system 1 including the same are basically the same as those of the first embodiment. Therefore, in the following description, the differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals. For the same reason, in FIG. 3, the same parts as in FIG. 1 are omitted.

  In the first embodiment, an ejector 35 is provided in the middle of the replenishment water path 8 to the water supply tank 7, and a leak steam path 39 is connected to the suction port 38 of the ejector 35. In the second embodiment, the leak steam path 39 is The pipe is directly piped into the water supply tank 7. Thereby, the leaked steam from the shaft seal portion of the steam motor 4 is directly blown into the stored water in the water supply tank 7 of the boiler 2. In this case, the replenishment water passage 8 to the water supply tank 7 is piped to the water supply tank 7 separately from the leakage steam passage 39.

  The configuration of the second embodiment is used when the back pressure to the shaft seal portion of the steam motor 4 is not a concern due to the pressure of the leaking steam. Compared with the first embodiment, there is no ejector 35 and the configuration is simple.

  By the way, in the second embodiment, an electric motor 43 is further provided in addition to the screw-type steam motor 4 as a prime mover for driving the compressor 5. In the illustrated example, a double-axis motor is used as the electric motor 43, and the rotary shaft provided so as to penetrate the electric motor 43 is connected to the output shaft of the steam motor 4 at one end and the input shaft of the compressor 5 to the other end. Connected. Thus, the compressor 5 can be driven by the steam motor 4 and can be driven by the electric motor 43 instead of or in addition to the steam motor 4. Other configurations and controls are the same as those in the first embodiment, and a description thereof will be omitted.

  FIG. 4 is a schematic view showing Example 3 of the leaked steam heat recovery structure 3 of the present invention. The leaked steam heat recovery structure 3 of the third embodiment and the steam utilization system 1 including the same are basically the same as those of the second embodiment. Therefore, in the following description, the differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

  In the third embodiment, a heat exchanger 44 is provided in the replenishment water channel 8 to the water supply tank 7. The heat exchanger 44 is supplied with makeup water to the water supply tank 7 and also leaked steam from the shaft seal portion of the steam motor 4. As a result, the replenishment water to the water supply tank 7 and the leaked steam from the shaft seal portion of the steam motor 4 can be indirectly heat-exchanged, and the water supply to the water supply tank 7 can be heated by the leaked steam. The leaked steam and its condensed water after heat exchange may be supplied to the water supply tank 7. Other configurations and controls are the same as those in the second embodiment, and a description thereof will be omitted. By the way, the heat exchanger 44 may be installed in the water supply tank 7, and the stored water in the water supply tank 7 may be heated by the leaked steam from the shaft seal portion of the steam motor 4.

  FIG. 5 is a schematic view showing Example 4 of the leaked steam heat recovery structure 3 of the present invention. The leaked steam heat recovery structure 3 of the fourth embodiment and the steam utilization system 1 including the same are basically the same as those of the second embodiment. Therefore, in the following description, the differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

  In the fourth embodiment, a leakage steam path 39 from the steam motor 4 is connected in the middle of the supply water path 8 to the water supply tank 7. That is, in the first embodiment, instead of installing the ejector 35 at the connection portion between the replenishment water passage 8 and the leak steam passage 39, the replenishment water passage 8 and the leak steam passage 39 are simply joined together. Also in this case, the leaked steam can be drawn into the replenishment water channel 8 by passing through the replenishment water channel 8.

  Further, as in the first embodiment, by mixing leaked steam into the makeup water supplied to the water supply tank 7, it is possible to suppress the steam blow-up compared to the case where the leaked steam is put directly into the water supply tank 7, and the heat The recovery rate can be improved. In addition, since the replenishment water path 8 to the water supply tank 7 and the leak steam path 39 from the shaft seal portion have at least a part of the common piping, the configuration can be simplified and the cost can be reduced. .

  Also in the fourth embodiment, similarly to the first embodiment, if necessary, the leakage steam path 39 may be provided with an atmosphere opening path 40 with a solenoid valve 41 and a pressure switch 42 so that the leakage steam can be opened to the atmosphere. Other configurations and controls are the same as those in the second embodiment, and a description thereof will be omitted.

  FIG. 6 is a schematic view showing Example 5 of the leaked steam heat recovery structure 3 of the present invention. The leakage steam heat recovery structure 3 of the fifth embodiment and the steam utilization system 1 including the same are basically the same as those of the fourth embodiment. Therefore, in the following description, the differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

  In the fifth embodiment, the replenishment water channel 8 is provided with a pump 45 downstream from the junction with the leakage steam channel 39. Due to the suction of the pump 45, the leaked steam from the shaft seal portion of the steam motor 4 is smoothly sucked into the supply water channel 8. However, the pump 45 may be installed in the leak steam path 39. In that case, the leaked steam from the shaft seal portion of the steam motor 4 is pushed into the water flow of the replenishment water channel 8. Other configurations and controls are the same as those in the fourth embodiment, and thus description thereof is omitted.

  The steam heat recovery structure 3 leaking from the shaft seal portion of the present invention and the steam utilization system 1 to which the steam heat recovery structure 3 is applied are not limited to the configurations of the above-described embodiments, and can be changed as appropriate. In particular, as long as the steam that leaks from the shaft seal portion of the steam motor 4 is used, the use location and the use method are not limited to the above embodiments. For example, in each said Example, although used for the preheating of the water supply to the boiler 2, you may utilize warm water other than the boiler 2. FIG.

  In FIG. 1, the heat exchange water pump 26 is installed in the replenishment water channel 8 to the water supply tank 7. However, when there is a raw water pressure, the installation of the heat exchange water pump 26 may be omitted. In this case, an electric valve may be installed in place of the heat exchange water supply pump 26, and the amount of water supplied to the heat exchanger 23 and thus the water supply tank 7 may be adjusted by adjusting the opening of the electric valve.

  Furthermore, in the said Example, although the heat exchanger 23 was set as the structure which cools both the lubricating oil and compressed air of the oil lubricated compressor 5, depending on the case, only one of lubricating oil and compressed air is used. It is good also as a structure to cool.

It is the schematic which shows an example of the vapor | steam utilization system to which Example 1 of the leak steam heat recovery structure of this invention was applied. It is the schematic which shows the shaft seal part of a screw type steam motor, and has shown it by making a part into a cross section. It is the schematic which shows Example 2 of the leak steam heat recovery structure of this invention. It is the schematic which shows Example 3 of the leak steam heat recovery structure of this invention. It is the schematic which shows Example 4 of the leak steam heat recovery structure of this invention. It is the schematic which shows Example 5 of the leak steam heat recovery structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steam utilization system 2 Boiler 3 Leakage steam heat recovery structure 4 Steam motor 5 Compressor 7 Water supply tank 8 Supply channel 21 Steam outlet 22 Non-contact seal 23 Heat exchanger 35 Ejector 36 Nozzle 37 Diffuser 38 Suction port 39 Leakage steam path 40 Open air path 41 Solenoid valve 42 Pressure switch 44 Heat exchanger 45 Pump

Claims (8)

Steam leakage recovery structure from a steam motor shaft seal, which supplies steam leaking from the shaft seal of a screw-type steam motor that generates power using steam to the location where the heat of the leaked steam is to be used. The leak steam heat recovery structure from the steam motor shaft seal according to claim 1, wherein leak steam from the shaft seal of the steam motor is supplied into the water stored in the water supply tank to the boiler. An indirect heat exchanger is installed in the water supply tank to the boiler or the supply water channel to this water supply tank.
The steam of the water supply tank or the water of the replenishment water channel is heated through the steam leaked from the shaft seal of the steam motor through the indirect heat exchanger. Leakage steam heat recovery structure. The leak steam heat recovery structure from the steam motor shaft seal according to claim 1, wherein the steam leaked from the shaft seal of the steam motor is supplied into a supply water channel to a water supply tank of the boiler. In the middle of the makeup channel, an ejector is provided,
5. The steam motor shaft seal according to claim 4, wherein water is passed through the makeup water channel, and the ejector sucks leaked steam from the shaft seal portion of the steam motor into the makeup water channel. Leaky steam heat recovery structure. 5. The leak steam path for supplying the steam leaked from the shaft seal portion of the steam motor to the makeup water path is opened to the atmosphere when the pressure in the leak steam path exceeds a set value. Item 6. A structure for recovering steam heat leaked from a steam motor shaft seal according to Item 5. A pump is provided in the leakage steam path for supplying the steam leaked from the shaft seal portion of the steam motor to the makeup water path and the leakage steam is discharged to the makeup water path, or a pump is provided in the middle of the makeup water path to remove the leakage steam. The leak steam heat recovery structure from the steam motor shaft seal according to claim 4, wherein the steam is sucked into the makeup water channel. The water in the replenishment channel is the leaked steam from the shaft seal portion of the steam motor after cooling the compressed air and / or lubricating oil as the fluid to be cooled from the oil lubricated compressor driven by the steam motor. It is heated and supplied to the water supply tank. The leak steam heat recovery structure from the steam motor shaft seal according to any one of claims 3 to 7.

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