JP5339073B2 - Steam system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a heat recovery amount from an exhaust gas, by using a plurality of still bodies different in steam pressures, as the still bodies of an exhaust gas boiler, and to enhance versatility of obtained steam obtained by pressure-rising steam of low vapor pressure. <P>SOLUTION: This stem system includes the upstream still body 3 passed with the exhaust gas, to generate the steam using heat of the exhaust gas, the downstream still body 5 passed with the exhaust gas after passed through the upstream still body 3, to generate the steam of pressure lower than that of the upstream still body 3, and a pressure rising mechanism 50 for rising pressure of the steam from the downstream still body 5, by the steam from the upstream still body 3. The pressure rising mechanism 50 is an ejector 51, for example. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a steam system including an exhaust gas boiler that generates steam using exhaust heat.

  Conventionally, exhaust gas boilers that generate steam using exhaust heat are well known. In the exhaust gas boiler, when the exhaust gas is passed, the water in the water pipe is heated and vaporized by the exhaust gas. Thereby, the vapor | steam of setting vapor pressure can be obtained from an exhaust gas boiler.

  In the exhaust gas boiler, the more the exhaust gas temperature at the inlet and the outlet is lower, in other words, the lower the exhaust gas temperature at the outlet is, the more efficient the heat recovery from the exhaust gas is. In order to effectively recover heat from the exhaust gas, the exhaust gas boiler only needs to have a large heat transfer area. However, no matter how large the heat transfer area, the exhaust gas temperature at the exhaust gas boiler outlet is related to the set steam pressure. There is a limit to lowering. This is because the exhaust gas temperature cannot be lowered below the saturation temperature at the set vapor pressure.

For example, when the set vapor pressure is 8 kgf / cm ² (= 0.78 MPa), the saturation temperature is 175 ° C., so that the exhaust gas temperature at the exhaust gas boiler outlet can be lowered only to about 190 ° C. in practice. An economizer is installed downstream of the exhaust gas boiler to preheat the water supply to the exhaust gas boiler, so that even when heat recovery from the exhaust gas is further promoted, the amount of evaporation of the exhaust gas boiler is small, so the amount of water supplied to the exhaust gas boiler is small, Therefore, the exhaust gas temperature at the economizer outlet can only be lowered to about 150 ° C.

  In order to further recover heat from the exhaust gas, as disclosed in the following patent documents, it is possible to install a plurality of exhaust gas boilers so that the set vapor pressure becomes lower as the exhaust gas flow goes downstream. Proposed. In this case, heat recovery efficiency can be improved by using a boiler having a lower set vapor pressure (lower saturation temperature) as the exhaust gas temperature decreases. However, it is meaningless and lacks versatility unless there is a demand for each steam with different steam pressures.

JP 59-150203 A Japanese Patent Laid-Open No. 11-350921

  The problem to be solved by the present invention is to improve the versatility of the steam obtained while effectively recovering heat from the exhaust gas.

The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is directed to an upstream can body through which exhaust gas is passed and steam is generated using the exhaust gas heat, and the upstream can body passes through the upstream can body. A downstream can body through which a later exhaust gas is passed and generates steam at a pressure lower than that of the upstream can body; and a booster mechanism that boosts the steam from the downstream can body with the steam from the upstream can body , The mechanism includes an ejector. The ejector sucks the steam from the downstream can body and mixes and discharges the steam from the both can bodies when the steam from the upstream can body is blown into the nozzle. And an intermediate-flow can body that generates steam at a lower pressure than the upstream can body and higher pressure than the downstream can body between the upstream can body and the downstream can body, The middle can body and the downstream can body are passed in order, and the downstream can The steam after the pressure from the booster mechanism is increased, the steam after the steam from the upstream can body is depressurized by the boost mechanism, and the steam from the midstream can body are equalized to each other. The pressure adjustment of the upstream can body is performed by adjusting the flow rate of the exhaust gas supplied to the upstream can body, and the pressure adjustment of the midstream can body is performed by adjusting the steam from the ejector and the midstream can body. The pressure adjustment valve provided in the steam path of the combined steam with the steam from, the pressure adjustment of the downstream can body, the suction valve provided in the steam path to the suction port of the ejector, and the other than the ejector The steam system is characterized by being controlled by a steam release valve that discharges steam to a location .

  According to the first aspect of the present invention, the plurality of cans are configured such that the set vapor pressure decreases as the exhaust gas flow goes downstream, in other words, the saturation temperature in the can decreases as the exhaust gas flow goes downstream. The body is installed. Thereby, the amount of heat recovered from the exhaust gas can be improved. Moreover, the use of steam can be broadened by increasing the pressure of the steam from the downstream can body with the steam from the upstream can body.

According to the first aspect of the present invention, the pressure from the downstream can body can be easily increased by the ejector.

According to the first aspect of the present invention, even if steam with different vapor pressures is obtained by improving the amount of heat recovered from the exhaust gas by using the upstream can body, the midstream can body and the downstream can body, The pressure can be adjusted and output.

The invention according to claim 2 is the steam system according to claim 1 , further comprising an economizer through which the exhaust gas after passing through the downstream can body is passed and preheats water supplied to each can body. is there.

According to the second aspect of the present invention, it is possible to more reliably recover the heat from the exhaust gas by installing an economizer that preheats the water supply to each can body. In addition, it is not necessary to supply water to all the cans through the economizer, and water may be supplied to some of the cans without using the economizer.

Furthermore, the invention described in claim 3 includes, as the economizer, a plurality of economizers through which the exhaust gas after passing through each can body is sequentially passed, and the economizers are installed upstream of the exhaust gas flow. The steam system according to claim 2 , wherein water is supplied to the can body installed upstream of the exhaust gas flow as the water is heated.

According to the invention described in claim 3 , the installation order of the economizer with respect to the flow direction of the exhaust gas is made to correspond to the installation order of the can body with respect to the flow direction of the exhaust gas. That is, the economizer installed on the upstream side is configured to supply water to the can body installed on the upstream side. Thereby, the amount of heat recovered from the exhaust gas can be further improved.

  According to the present invention, by using a plurality of cans, the versatility of the resulting steam can be enhanced by using the pressure increasing mechanism while effectively recovering heat from the exhaust gas.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows Example 1 of the steam system of this invention, and has shown it notched partially. FIG. 2 is a schematic plan view of an exhaust gas boiler used in the steam system of FIG. 1, with a part cut away. It is the schematic which shows Example 2 of the steam system of this invention. It is the schematic which shows Example 3 of the steam system of this invention. It is the schematic which shows an example of the water supply system to each can body in Example 1 and Example 2, and has shown only the can body and the economizer. It is the schematic which shows the other example of the water supply system to each can body in Example 1 and Example 2, and has shown only the can body and the economizer. It is the schematic which shows another example of the water supply system to each can in Example 1 and Example 2, and only the can and the economizer are shown.

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

  FIG. 1 is a schematic view showing a first embodiment of a steam system 1 according to the present invention, which is partially cut away. FIG. 2 is a schematic plan view of the exhaust gas boiler 2 used in the steam system 1 and is partially cut away.

  The steam system 1 of this embodiment includes an exhaust gas boiler 2 that generates steam using exhaust heat, and the exhaust gas boiler 2 includes a plurality of cans 3, 4, and 5. In the present embodiment, the three can bodies of the first can body 3, the second can body 4 and the third can body 5 are installed in series along the exhaust gas flow. Therefore, the first can body 3 can also be called an upstream can body, the second can body 4 can be called a midstream can body, and the third can body 5 can be called a downstream can body.

  Each of the cans 3 to 5 can be configured in the same manner as various conventionally known exhaust gas boilers, regardless of the configuration, but in the illustrated example, it is a multi-pipe once-through boiler. Specifically, each of the cans 3 to 5 is configured by connecting the upper headers 6 to 8 and the lower headers 9 to 11 with a large number of water tubes 12 to 14. The upper headers 6 to 8 and the lower headers 9 to 11 are spaced apart in parallel in the vertical direction, and the inside is formed to be hollow. On the other hand, each water pipe 12-14 is arrange | positioned perpendicularly | vertically, and while an upper end part is connected to the upper headers 6-8, a lower end part is connected to the lower headers 9-11. Although not shown, the connection parts between the upper and lower headers 6 to 11 and the water pipes 12 to 14 are covered with a fireproof material.

  Although arrangement | positioning of the water pipes 12-14 in each can 3-5 is set suitably, while being arrange | positioned perpendicularly | vertically with the flow direction of waste gas, it is arrange | positioned also with multiple flow direction of waste gas. At that time, a gap through which the exhaust gas is passed is opened between the adjacent water pipes, and the water pipes are arranged in a staggered manner in the illustrated example. In addition, the water pipes 12 to 14 may be provided with fins, studs, or the like on the outer peripheral surface as desired to increase the heat transfer area.

  Each can body 3 to 5 is covered with a can body cover 15 except for the entrance and exit of the exhaust gas so that the exhaust gas flows in order to the first can body 3, the second can body 4 and the third can body 5. At this time, each of the can bodies 3 to 5 may be covered with a common can body cover 15, or the can bodies 3 to 5 may be covered with the can body cover 15 except for the inlet / outlet of the exhaust gas, and connected to each other by a flange or a pipe. May be. That is, while connecting the exhaust gas outlet of the can body cover of the first can body 3 and the exhaust gas inlet of the can body cover of the second can body 4, the exhaust gas outlet of the can body cover of the second can body 4 and the third can body The exhaust gas inlet of the can body cover 5 may be connected. In this case, a plurality of independently configured exhaust gas boilers are connected in series. In any case, it goes without saying that the can body cover 15 may be provided with a heat insulating material or a refractory material.

  Water (usually soft water) is supplied to the lower headers 9 to 11 through the water supply channels 16 to 18 to the cans 3 to 5, and the water is heated by the exhaust gas in the water tubes 12 to 14 and is vaporized. Is done. The steam is led out from the upper headers 6 to 8 through the steam separators 19 to 21. Moreover, the water in each can 3-5 can be discharged | emitted from the lower headers 9-11 via the drainage channels 22-24 if desired. By opening the drainage valves 25 to 27 provided in the drainage channels 22 to 24, drainage can be achieved from the cans 3 to 5.

  The steam / water separators 19 to 21 are centrifugal steam / water separators in this embodiment. Specifically, the steam separators 19 to 21 are provided with longitudinally cylindrical cylinders 28 to 30, and steam is introduced into the cylinders 28 to 30 in a tangential direction. Accordingly, the steam from the upper headers 6 to 8 swirls within the barrels 28 to 30, and the centrifugal force causes the water to be blown outward and to drop downward, thus improving the dryness. Steam is led out from the top of the barrels 28-30. In addition, the water separated in the trunks 28 to 30 is returned to the lower headers 9 to 11 through the separated water return pipes 31 to 33.

  In the present embodiment, water supply to the lower headers 6 to 8 of the cans 3 to 5 is preheated by the economizers 34 to 36. Specifically, economizers 34 to 36 are installed downstream of the exhaust gas boiler 2. In the illustrated example, the first can body 3, the second can body 4, the third can body 5, and the economizers 34 to 36 are covered with a common can body cover 15, but separately from the exhaust gas boiler 2, the economizer 34 to 35 and the exhaust gas outlet of the exhaust gas boiler 2 and the exhaust gas inlet of the economizer 34 may be connected by a flange or piping.

  In this embodiment, the economizers 34 to 35 are installed in the number of cans 3 to 5 and are installed in series along the exhaust gas flow. In this case, it is preferable that the economizers 34 to 35 preheat the water supplied to the can body installed upstream of the exhaust gas flow as it is installed upstream of the exhaust gas flow.

  Specifically, the first economizer 34, the second economizer 35, and the third economizer 36 are installed in order along the exhaust gas flow. 35 preheats the water supply to the second can body 4, and the third economizer 36 preheats the water supply to the third can body 5. And the water pre-heated by each economizer 34-36 is supplied to the lower headers 9-11 of each can 3-5. The presence or absence of water supply to each of the cans 3 to 5 controls the operation of the water supply pumps 37 to 39 to the economizers 34 to 36 based on the detection result of the water level detector (not shown) of each of the cans 3 to 5. Can be switched.

  In the exhaust gas boiler 2 and the economizers 34 to 36, exhaust gas is introduced through the exhaust gas introduction path 40, and exhaust gas is led out through the exhaust gas outlet path 41. While the exhaust gas passes through the exhaust gas boiler 2, heat exchange between the exhaust gas and the water pipes 12 to 14 is performed, and the exhaust gas is cooled while the water in the water pipes 12 to 14 is heated and vaporized. Further, while the exhaust gas passes through the economizers 34 to 36, the water supplied to the cans 3 to 5 is preheated by the exhaust gas.

  The exhaust gas introduction path 40 and the exhaust gas outlet path 41 are connected by a bypass path 42. Then, it is possible to selectively switch whether the exhaust gas is discharged via the exhaust gas boiler 2 or the bypass passage 42, or to adjust the distribution ratio of both. Thereby, the evaporation amount by the exhaust gas boiler 2 can be adjusted. Therefore, in this embodiment, a three-way damper 43 is provided at a branch portion between the exhaust gas introduction path 40 and the bypass path 42. However, a damper may be separately provided in each of the exhaust gas introduction path 40 and the bypass path 42 downstream of the branch portion between the exhaust gas introduction path 40 and the bypass path 42, and the opening / closing or opening degree of each damper may be adjusted.

  The three-way damper 43 includes a box-shaped valve box 44, and the valve box 44 is provided with one exhaust gas inlet 45 and two exhaust gas outlets 46 and 47. Of the two exhaust gas outlets 46 and 47, one (46) is connected to the exhaust gas introduction path 40 to the exhaust gas boiler 2 and the other (47) is connected to the bypass path 42. In addition, a damper 48 is provided in the valve box 44, and the supply flow rate to the exhaust gas boiler 2 and the supply to the bypass passage 42 with respect to the exhaust gas from the exhaust gas inlet 45 by adjusting the position of the damper 48. The distribution ratio with the flow rate can be adjusted. Specifically, the distribution ratio is adjusted by controlling the motor 49 that drives the damper 48 and adjusting the rotation stop position of the damper 48. However, as described above, the damper 48 may be controlled to selectively open one of the two exhaust gas outlets 46 and 47 and close the rest as desired.

The first can body 3, the second can body 4 and the third can body 5 are appropriately designed for their vapor pressure and evaporation amount, but in order to improve the amount of heat recovered from the exhaust gas, It is preferable to design the vapor pressure to decrease as it goes to. For example, the first can of body 3 ^{8kgf / cm 2 (= 0.78MPa)} , the second cans body 4 ^{5kgf / cm 2 (= 0.49MPa)} , third cans body 5 3kgf ^/ cm 2 (= 0. 29 MPa).

  As described above, steam having different pressures is generated from the plurality of cans 3 to 5, and the steam system 1 of the present embodiment includes a boosting mechanism 50 that boosts low-pressure steam using high-pressure steam. Thereby, even if low-pressure steam is obtained in order to improve the heat recovery amount from the exhaust gas, inconvenience due to the lack of demand can be avoided.

Specifically, the booster mechanism 50 of this embodiment includes an ejector 51. The ejector 51 includes a nozzle and a diffuser, and by ejecting a high-pressure fluid from the nozzle toward the diffuser, the ejector 51 sucks the low-pressure fluid from the suction port, and mixes and discharges both fluids. Here, the first steam path 52 through which the steam from the first can body 3 passes is connected to the nozzle, and the third steam path 54 through which the steam from the third can body 5 passes is connected to the suction port. Yes. Therefore, the steam from the first can body 3 is sucked into the ejector 51 by blowing the steam from the first can body 3 into the nozzle. Both steams are mixed and discharged. During this time, the steam from the first can body 3 is depressurized, while the steam from the third can body 5 is pressurized. Here, the pressure of the mixed steam is, for example, 5 kgf / cm ² (= 0.49 MPa). Therefore, the steam from the second can body 4 can be joined to the steam from the ejector 51 via the second steam path 53.

  The steam from the ejector 51 is led to the fourth steam path 55. The steam in the fourth steam path 55 can be supplied to various steam-using facilities via a steam header 56 as desired. Steam from a boiler (fuel-fired boiler or electric boiler) 57 can be supplied to the steam header 56 as desired. A pressure adjustment valve 58 is provided in the fourth steam path 55.

  Incidentally, a steam supply valve 59 is provided in the first steam path 52, and a suction valve 60 is provided in the third steam path 54. The steam supply valve 59 and the suction valve 60 can be opened and closed or changed in opening degree. Further, the third can body 5 is provided with a steaming valve 61 so that steam can be discharged to places other than the ejector 51. This evaporative valve 61 can also be opened / closed or changed in opening degree. The evaporating valve 61 may be provided in the third steam path 54 upstream from the suction valve 60. In that case, the suction valve 60 and the evaporating valve 61 may be shared and configured by a three-way valve.

  The pressure of the first can 3 is adjusted by adjusting the position of the damper 48 of the three-way damper 43 to adjust the flow rate of exhaust gas supplied to the exhaust gas boiler 2. Specifically, the pressure in the first can 3 is monitored by the first sensor 62 (temperature may be used in some cases), and the motor 49 is controlled so as to maintain the vapor pressure from the first can 3 as desired. The position of the damper 48 is adjusted by controlling.

  The pressure adjustment of the second can body 4 is performed by the pressure adjustment valve 58. That is, the pressure adjustment valve 58 provided in the fourth steam path 55 adjusts the opening degree so as to maintain the primary side (upstream side) pressure as desired. The pressure adjustment valve 58 is configured to adjust the opening degree by itself in this embodiment, but the opening degree is adjusted based on the pressure detected by the second sensor 63 provided in front of the pressure adjusting valve 58 (which may be a temperature in some cases) if desired. Also good.

  However, the pressure adjustment of the second can 4 may be controlled by a boiler 57 that supplies steam to the steam header 56 instead of such control. That is, the steam from the second can body 4 is supplied as it is to the steam header 56 without providing the pressure regulating valve 58 in the fourth steam path 55, and the boiler is maintained so that the steam pressure in the steam header 56 is maintained as desired. The amount of combustion of 57 may be controlled. In addition to the adjustment by the pressure adjustment valve 58, such adjustment by the boiler 57 may be performed.

  In adjusting the pressure of the third can body 5, the third sensor 64 monitors the pressure in the third can body 5 (temperature may be used in some cases) so that the vapor pressure from the third can body 5 is maintained as desired. In addition, the suction valve 60 and the evaporating valve 61 are controlled.

  By the way, when the use load of the steam does not decrease, the detection pressure of the second sensor 63 increases. If it exceeds the set value, the steam supply valve 59 and the suction valve 60 are controlled to The steam supply from the can 3 and the third can 5 through the ejector 51 may be limited. Alternatively, or in addition thereto, the motor 49 of the three-way damper 43 may be controlled to limit the amount of exhaust gas supplied to the exhaust gas boiler 2 to limit the amount of evaporation by the exhaust gas boiler 2.

  In addition, when starting the steam system 1, it is preferable to close the suction valve 60 until the vapor pressure of the first can body 3 reaches a predetermined value. And if the vapor pressure of the 1st can 3 rises to a setting, the suction valve 60 should just be opened. As a result, the ejector 51 can exhibit its intended function.

In the present embodiment, for example, the first can body 3 is 69 kg / h at 8 kgf / cm ² (= 0.78 MPa), the second can body 4 is 149 kg / h at 5 kgf / cm ² (= 0.49 MPa), The three can bodies 5 are set to 41 kg / h at 3 kgf / cm ² (= 0.29 MPa). The exhaust gas temperatures are 408 ° C. at the inlet of the first can body 3, 216 ° C. at the inlet of the second can body 4, 173 ° C. at the inlet of the third can body 5, and 160 ° C. at the outlet of the third can body 5. And 100 ° C. at the exit of the economizer 36. Then, steam after the steam from the first can body 3 is decompressed by the ejector 51, steam after the steam from the third can body 5 is pressurized by the ejector 51, and steam from the second can body 4 Are mixed to obtain an evaporation amount of 881 kg / h at 5 kgf / cm ² (= 0.49 MPa). This means that even if the exhaust gas boiler 2 includes three can bodies 3 to 5, it can be regarded as one can body (5 kgf / cm ² , 881 kg / h).

On the other hand, if the first can body 3, the second can body 4 and the third can body 5 are originally composed of one can body, in other words, the exhaust gas boiler 2 is composed of only one can body. At 5 kgf / cm ² (= 0.49 MPa), the exhaust gas temperature is 408 ° C. at the common can body inlet, 175 ° C. at the common can body outlet, and 123 ° C. at the economizer outlet. .

  Therefore, the steam system 1 of this embodiment has a lower exhaust gas temperature at the outlet of the exhaust gas boiler 2 and the economizer 36 and a higher heat recovery amount. Further, by increasing the amount of evaporation in the exhaust gas boiler 2, the amount of water passing through the economizers 34 to 36 is increased, so that the heat recovery in the economizers 34 to 36 is made more effective.

  FIG. 3 is a schematic view showing a second embodiment of the steam system 1 of the present invention, and a part thereof is omitted. The steam system 1 according to the second embodiment is basically the same as 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.

  In the first embodiment, the ejector 51 is used to depressurize the steam from the first can body 3 while the steam from the third can body 5 is increased. In the second embodiment, the steam engine 65 is used. The steam from the first can body 3 is depressurized, while the steam from the third can body 5 is increased using the steam compressor 66 driven by the steam engine 65.

  That is, the steam system 1 according to the second embodiment includes a steam engine 65 that generates power using steam and a steam compressor 66 that is driven by the steam engine 65 as the pressure increasing mechanism 50.

  The steam engine 65 is a screw-type steam engine in this embodiment. A screw-type steam engine is an apparatus in which steam is introduced between screw rotors that mesh with each other, and the steam is expanded and decompressed while rotating the screw rotor by the steam, and power is obtained by rotation of the screw rotor at that time. However, the steam engine 65 is not limited to a screw-type steam engine as long as it generates power using steam. For example, a steam turbine or a reciprocating steam engine using reciprocating piston movement may be used.

  The type of the vapor compressor 66 is not particularly limited, but is, for example, a screw type vapor compressor. A screw-type steam compressor is a device that sucks steam between screw rotors that rotate while meshing with each other, and compresses and discharges the steam by rotation of the screw rotor. However, the steam compressor 66 is not limited to a screw type as long as it compresses and discharges steam, and may be a reciprocating type.

  In the present embodiment, the steam from the first can body 3 is supplied to the steam engine 65 via the first steam path 52. The steam supplied to the steam engine 65 is expanded and depressurized by working in the steam engine 65, and is discharged to the fourth steam path 55. The steam compressor 66 driven by the steam engine 65 sucks, compresses and discharges the steam from the third can body 5. In this way, the steam after the steam from the third can body 5 has been pressurized by the steam compressor 66 and the steam after the steam from the first can body 3 has been decompressed by the steam engine 65 are merged, and Similarly to the first embodiment, the steam from the second can 4 is also merged. Other configurations and controls are the same as those in the first embodiment, and thus description thereof is omitted.

  FIG. 4 is a schematic view showing a third embodiment of the steam system 1 of the present invention, and a part thereof is omitted. The steam system of the third embodiment is basically the same as that 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.

  In the first embodiment, the economizers 34 to 36 corresponding to the number of the cans 3 to 5 are provided, but in the third embodiment, the economizer 67 is one. In this case, the water preheated by the economizer 67 common to the cans 3 to 5 is branched and supplied to the cans 3 to 5. With the water supply pump 68 activated, the water supply valves 69 to 71 individually provided in the water supply passages 16 to 18 to the cans 3 to 5 are controlled to individually supply water to the cans 3 to 5. Can be controlled. Other configurations and controls are the same as those in the first embodiment, and a description thereof will be omitted.

  By the way, it is similarly applied not only to the said Example 1 but the said Example 2 to make the economizer 67 common to each can 3-5. That is, the plurality of economizers 34 to 36 in FIG. 3 may be shared to form one economizer 67 as shown in FIG. 4, and water can be supplied from the common economizer 67 to each of the cans 3 to 5.

  Further, in FIG. 4, the water from the common economizer 67 passes through the common water supply pump 68 and then branches to be supplied to each of the cans 3 to 5, and the water supply path 16 to each of the cans 3 to 5. Although the water supply to each can body 3-5 was controlled by the water supply valves 69-71 provided in -18, it replaced with the common water supply pump 68 and each water supply valve 69-71 to each can body 3-5. You may install a water supply pump in the water supply channels 16-18. In this case, the water from the common economizer 67 is branched and supplied to the cans 3 to 5, and each can is provided by a water supply pump provided individually in the water supply passages 16 to 18 to the cans 3 to 5. Water supply to the bodies 3 to 5 is individually controlled.

  Next, the type of the water supply system to each can 3-5 in the said Example 1 and the said Example 2 is demonstrated. FIG. 5 to FIG. 7 are schematic views showing types of water supply methods to the cans 3 to 5 in the steam systems 1 of the first and second embodiments. The cans 3 to 5 and the economizers 34 to 36 are shown in FIG. Only shows. 5 to 7, the water from the water supply pump 72 branches after passing through the check valve 73 and passes to the economizers 34 to 36 through the water supply valves 74 to 76 and the check valves 77 to 79, respectively. After being supplied and preheated by the economizers 34 to 36, the cans 3 to 5 are supplied. In this case, whether or not to supply water to the economizers 34 to 36 and the cans 3 to 5 can be switched by controlling the opening and closing of the water supply valves 74 to 76 with the water supply pump 72 activated. However, as shown in FIG. 1 and FIG. 3, by providing water supply pumps 37 to 39 for each economizer 34 to 36 and controlling each of the water supply pumps 37 to 39, each economizer 34 to 36 and each can 3 to 36 are controlled. The presence or absence of water supply to 5 may be switched.

  In FIG. 5, the economizers 34 to 36 are installed in series along the exhaust gas flow. When a plurality of economizers are installed, the economizers 34 to 36 are installed on the upstream side of the exhaust gas flow as they are installed on the upstream side of the exhaust gas flow. The example which preheats the water supply to the can body which is done is shown. Here, in order from the upstream side of the exhaust gas flow, the first can body 3, the second can body 4 and the third can body 5 are installed, and then, if desired, the first economizer 34, the second economizer 35 and the third economizer. Any one or more of 36 are installed.

  In FIG. 6, the economizers 34 to 36 are installed in series along the exhaust gas flow. When a plurality of economizers are installed, the economizers 34 to 36 are installed more downstream in the exhaust gas flow. The example which preheats the water supply to the can body which is done is shown. Here, in order from the upstream side of the exhaust gas flow, the first can body 3, the second can body 4 and the third can body 5 are installed, and then, if desired, a third economizer 36, a second economizer 35 and a first economizer. Any one or more of 34 are installed.

  FIG. 7 shows an example in which the economizers 34 to 36 are installed in parallel along the exhaust gas flow. Here, in order from the upstream side of the exhaust gas flow, the first can body 3, the second can body 4 and the third can body 5 are installed, and then, if desired, the first economizer 34, the second economizer 35 and the third economizer. Any one or more of 36 are installed in parallel.

  In any case, first, there is a pattern in which the economizers 34 to 36 are not installed at all and water is supplied to the cans 3 to 5 without an economizer. Alternatively, only one of the first economizer 34, the second economizer 35, and the third economizer 36 is installed, and any one of the first can body 3, the second can body 4, and the third can body 5 is installed. Only one water is supplied through an economizer, but there is a pattern in which water is supplied to other cans without an economizer.

  Further, any two of the first economizer 34, the second economizer 35, and the third economizer 36 are installed, and any one of the first can body 3, the second can body 4, and the third can body 5 is installed. One water is supplied through an economizer, but there is also a pattern in which the remaining cans are supplied without an economizer. For example, the first economizer 34 and the second economizer 35 are installed as shown by a solid line and a one-dot chain line in FIG. That is, water is supplied to the first can body 3 via the first economizer 34, water is supplied to the second can body 4 via the second economizer 35, and water is supplied to the third can body 5 without the economizer. In this case, the amount of heat recovered from the exhaust gas can be increased, and condensation in the economizer can be prevented.

  Further, there is a pattern in which all of the first economizer 34, the second economizer 35, and the third economizer 36 are installed. That is, water is supplied to the first can body 3 via the first economizer 34, water is supplied to the second can body 4 via the second economizer 35, and water is supplied to the third can body 5 via the third economizer 36. Supply water.

  The steam system 1 of the present invention is not limited to the above-described embodiments and can be changed as appropriate. In particular, a plurality of cans are installed, steam is generated by using exhaust heat in each can, and steam from the can placed on the upstream side is placed downstream and lower in vapor pressure. If it is the structure which pressurizes the vapor | steam from a can body, various structures and control including the pressure | voltage rise mechanism 50 can be changed suitably.

  For example, in FIG. 1, the second can body 4 may be omitted, or the vapor pressure of the second can body 4 may be equivalent to that of the first can body 3. Further, the vapor pressure of the second can body 4 may be different from the vapor pressure after the vapor from the third can body 5 is increased by the ejector 51. In that case, the steam from the second can body 4 is used without being merged into the fourth steam path 55. Further, using the steam from the second can body 4, the pressure from the third can body 5 is increased by the pressurizing mechanism 50, or the second can can be increased by using the steam from the first can body 3. The pressure from the body 4 may be increased. It goes without saying that the presence or absence of the merge of the steam paths 52 to 55 is changed accordingly.

  Moreover, in each said Example, although the one or some economizer 34-36,67 was installed downstream of the exhaust gas boiler 2, installation of an economizer is not essential. Furthermore, in each said Example, although the three can bodies 3-5 were provided, the number of can bodies can be changed suitably. Moreover, the vapor pressure and evaporation amount of each can 3-5 can also be changed suitably.

1 Steam System 2 Exhaust Gas Boiler 3 First Can Body (Upstream Can Body)
4 Second can (middle-stream can)
5 Third can body (downstream can body)
34 1st economizer 35 2nd economizer 36 3rd economizer 50 Boosting mechanism 51 Ejector 65 Steam engine 66 Steam compressor 67 Economizer

Claims (3)

An upstream can body through which exhaust gas is passed and generates steam using the exhaust gas heat;
The exhaust gas after passing through this upstream can body is passed, and a downstream can body that generates steam at a lower pressure than the upstream can body,
A pressure increasing mechanism for increasing the pressure of the steam from the downstream can body with the steam from the upstream can body ,
The boost mechanism includes an ejector,
The ejector, by steam from the upstream boiler body to the nozzle is blown, sucks steam from the downstream boiler body, and discharging a mixture of vapor from the two can body,
Further comprising a midstream can body that generates steam at a lower pressure than the upstream can body and higher pressure than the downstream can body between the upstream can body and the downstream can body,
The exhaust gas is passed through the upstream can body, the midstream can body and the downstream can body in order,
The steam after the steam from the downstream can body has been pressurized by the pressurizing mechanism, the steam after the steam from the upstream can body has been decompressed by the pressurizing mechanism, and the steam from the midstream can body have a pressure. Mixed by equalizing each other ,
The pressure adjustment of the upstream can body is made by adjusting the exhaust gas flow rate supplied to the upstream can body,
The pressure adjustment of the intermediate flow can body is performed by a pressure adjustment valve provided in the steam path of the combined steam of the steam from the ejector and the steam from the intermediate flow can body,
The pressure adjustment of the downstream can body is performed by controlling a suction valve provided in a steam path to the suction port of the ejector and a steaming valve that discharges steam to a place other than the ejector. Steam system. The steam system according to claim 1 , further comprising an economizer through which the exhaust gas after passing through the downstream can body is passed and preheats water supplied to each can body. As the economizer, comprising a plurality of economizers through which the exhaust gas after passing through each can body is passed in order,
The steam system according to claim 2 , wherein the plurality of economizers preheats water supplied to a can body installed upstream of the exhaust gas flow as it is installed upstream of the exhaust gas flow.

Images