JP5739229B2 - Superheated steam generator - Google Patents

Description

  The present invention generates superheated steam by heating water with combustion gas generated by combustion of a burner to generate saturated steam, and further heating saturated steam with combustion gas after heating water to generate superheated steam Related to the vessel.

  As a conventional superheated steam generator, for example, Patent Document 1 discloses a saturated steam generation unit that generates water vapor by heating water with a combustion gas generated by burner combustion, and a combustion gas that has passed through the steam generation unit. Discloses a superheated steam generator that is integrally provided with a superheated steam generator that heats saturated steam to generate superheated steam. According to this superheated steam generator, in the saturated steam generating section, the heating pipe is heated from outside with combustion gas, etc., and the water flowing in the heating pipe is heated to obtain saturated steam, and further the superheated steam generating section In the above, superheated steam is obtained by heating the saturated steam using combustion gas or the like. Here, the heating of the saturated steam in the superheated steam generator is performed using the combustion gas generated by heating the water and generating the saturated steam, so that it is considered that energy saving can be favorably achieved.

JP 2008-32235 A

  However, in the superheated steam generator of Patent Document 1, since water for generating saturated water vapor is introduced into the heating pipe, if water treatment is neglected, scale accumulates in the heating pipe and the pipe is clogged. There was a problem that occurred. Combustion gas generated by burner combustion is used for heating to generate saturated water vapor and heating to generate superheated steam, but immediately after generating superheated steam, exhaust gas is still in a high temperature state. It had been. Therefore, there is room for further energy saving by using the remaining heat of the exhausted combustion gas more effectively.

  In addition, it is desired to reduce the size and speed of startup of superheated steam generators for household and small-scale business applications. To that end, it is necessary to take a large temperature difference during heat exchange, It is conceivable to supply combustion gas. In this case, the casing, the heating pipe, and the like are exposed to the high-temperature combustion gas, and a large thermal stress is generated, for example, at a folded portion of the heating pipe or a connection portion between the heating pipe and the casing. For this reason, cracks, pipe cracks, and the like occur in the heating pipe and the like, causing a problem that the service life of the superheated steam generator is shortened.

  The present invention has been made in view of such circumstances, and an object of the present invention is to make the residual heat of the combustion gas more effective with a piping structure that can suppress thermal stress generated by heating with the combustion gas without causing clogging of the piping. It is to provide a superheated steam generator that can be utilized.

To achieve the above object, the superheated steam generator according to the present invention comprises:
This is a superheated steam generator that heats water with combustion gas generated by combustion of a burner to generate saturated steam, and further heats saturated steam with the combustion gas after heating the water to generate superheated steam. The feature configuration is
The cylindrical pressure vessel that contains water is disposed below the surface of the contained water, and combustion gas is introduced into the inside of the pressure vessel from one side in the axial direction of the pressure vessel. A furnace tube that circulates toward the side, a first smoke tube that circulates the combustion gas that has passed through the furnace tube from the other side in the axial direction toward the one side, and a combustion gas that has passed through the first smoke tube as the shaft. A second smoke pipe that circulates from one side of the direction toward the other side, a first header that guides and circulates the combustion gas that has passed through the furnace tube to the first smoke pipe, and the combustion gas that has passed through the first smoke pipe. A second header that guides and distributes the second smoke pipe,
The furnace tube is connected and supported to the inner wall on one side of the pressure vessel,
The first header is supported from the furnace tube in the vicinity of the other end portion of the furnace tube, and is disposed in a non-contact state with a space in the axial direction from the inner wall on the other axial side of the pressure vessel. And
The second header is supported from the furnace tube in the vicinity of the other end portion of the furnace tube through the first header and the first smoke pipe, and is slidably passed through the furnace tube. and,
In the pressure vessel, the first smoke pipe is disposed above the second smoke pipe,
The second smoke pipe is provided so as to be slidably penetrated with respect to the first header .

  That is, in this configuration, the first header is supported from the furnace tube in the vicinity of the other end of the furnace tube, and the second header is also provided on the other side of the furnace tube via the first header and the first smoke tube. It is supported from the furnace tube near the end. Therefore, according to the above characteristic configuration, in the cylindrical pressure vessel containing water, the combustion gas is introduced into the furnace tube disposed below the water surface, and the combustion gas is circulated inside the furnace tube. Thus, water outside the furnace tube can be heated to generate water vapor. In addition, since combustion gas flows inside the furnace tube and water flows outside the furnace tube, the inside of the furnace tube is not clogged due to the generation of scale caused by water. Similarly, since the combustion gas is circulated in the first and second smoke pipes, the inside of the first and second smoke pipes is not clogged by the generation of scale caused by water.

In addition, the first header is disposed at an axial distance from the inner wall on the other side in the axial direction of the pressure vessel, so that water exists between the first header and the inner wall of the pressure vessel. Therefore, the first header is cooled by this water, heat transfer from the first header to the inner wall of the pressure vessel can be suppressed, and temperature rise of the inner wall of the pressure vessel can be prevented. . Moreover, by cooling the 1st header with the water which exists between the 1st header and the inner wall of a pressure-resistant container, water is heated as a result, and water vapor | steam can be generated efficiently.
Here, since a high-temperature combustion gas is introduced into the first header, thermal expansion occurs. Thereby, when the 1st header and the inner wall of a pressure vessel are connected, it is possible that a thermal stress generate | occur | produces. On the other hand, as in this feature configuration, the first header is disposed in a non-contact state with a space from the inner wall of the pressure vessel, and the first header is configured to allow thermal expansion of the first header. Generation of thermal stress generated between the inner wall of the pressure vessel and the first header, the joint between the first header and the first smoke pipe, and the occurrence of distortion, cracks, breakage, etc. in the inner wall of the pressure vessel are prevented. be able to.

  Furthermore, since a high-temperature combustion gas is introduced into the furnace tube, thermal expansion occurs. Similarly, thermal expansion occurs in the second header due to the introduction of the combustion gas. However, since the combustion gas having a relatively low temperature is introduced into the second header located downstream of the furnace tube, the thermal expansion thereof is performed. The rates are different, and it is considered that thermal stress is generated when the furnace tube and the second header are connected. On the other hand, as in this feature configuration, the second header is provided by slidably penetrating the furnace tube, thereby allowing thermal expansion based on temperature changes of the second header and the furnace tube. The generation of thermal stress between the second header and the furnace tube can be eliminated, and the occurrence of distortion, cracks, breakage, etc. in the second header, the joint between the second header and each smoke tube, and the furnace tube can be prevented. it can.

Further , since the first smoke pipe is disposed above the second smoke pipe, the structure of the flow path of the combustion gas in the pressure vessel is the same as that of the combustion gas passing through the furnace tube via the first header. It can be set as the structure guide | induced to the 1st smoke pipe located above 2 smoke pipes, and after that to the 2nd smoke pipe located below the 1st smoke pipe through a 2nd header. Thereby, the combustion gas which passed the furnace tube can be distribute | circulated to the 1st smoke pipe in the position above the 2nd smoke pipe inside a pressure vessel. Therefore, the position above the second smoke pipe inside the pressure vessel can be efficiently heated by the relatively high-temperature combustion gas immediately after passing through the furnace tube circulating in the first smoke pipe.

Furthermore , the 2nd smoke pipe is provided so that sliding with respect to the 1st header is possible. Here, the first header undergoes thermal expansion when a high-temperature combustion gas is introduced. Similarly, the combustion gas is also expanded in the second smoke pipe by introduction, but since the combustion gas having a relatively low temperature is introduced into the second smoke pipe located downstream of the first header, the heat of the combustion gas is increased. The expansion coefficients are different, and thermal stress is generated when the first header and the second smoke pipe are connected. On the other hand, since the second smoke pipe is slidably penetrated with respect to the first header as in this characteristic configuration, thermal expansion due to heating of the first header and the second smoke pipe is allowed. Structured. Thereby, generation | occurrence | production of the thermal stress between a 1st header and a 2nd smoke pipe can be eliminated, and generation | occurrence | production of a distortion, a crack, a failure | damage, etc. in a 1st header or a 2nd smoke pipe can be prevented at least.

A further characteristic configuration of the superheated steam generator according to the present invention is that the furnace tube is configured as a single unit,
The first smoke pipe constituting the superheated steam generator for heating the saturated steam to generate superheated steam is disposed on the surface of the water contained in the pressure vessel,
The second smoke pipe constituting the saturated water vapor generating section for heating the water to generate saturated water vapor is located below the surface of the water contained in the pressure vessel together with the furnace tube.

According to the above characteristic configuration, the first smoke pipe is disposed on the surface of the water contained in the pressure vessel, and is configured as a superheated steam generator that generates saturated steam by heating saturated steam with combustion gas. Yes. Thereby, saturated steam can be heated with the 1st smoke pipe, and superheated steam can be generated. Here, since a relatively high-temperature combustion gas immediately after passing through the furnace tube flows through the first smoke tube, the temperature difference from the saturated steam to be heated increases, so that heat transfer can be increased and even in a small heat transfer area. A predetermined superheated steam can be generated.
And the 2nd smoke pipe located downstream of the 1st smoke pipe is arrange | positioned under the surface of the water accommodated in the pressure-resistant container, and is comprised as a water vapor | steam generation part which heats water with the said combustion gas and generate | occur | produces water vapor | steam. ing. Thus, saturated water vapor can be generated by heating the water through the second smoke pipe. Although the combustion gas whose temperature has decreased due to the heating of the saturated steam in the first smoke pipe is introduced into the second smoke pipe, the temperature is sufficient to heat the water and generate saturated steam. Saturated water vapor can be efficiently generated by effectively using heat. Therefore, the superheated steam can be generated with high thermal efficiency by configuring the first and second smoke pipes as described above.

  According to a further feature of the superheated steam generator according to the present invention, a partition plate for partitioning the saturated steam generation unit and the superheated steam generation unit is provided inside the pressure-resistant container, and the partition plate is formed of the partition plate. The flow of saturated water vapor that circulates in the superheated steam generator and the flow of combustion gas that circulates in the first smoke pipe constitute an opposing flow.

  According to the above characteristic configuration, in the superheated steam generator, the flow of the saturated steam and the flow of the combustion gas in the first smoke pipe constitute a counter flow, so that the combustion gas exchanged heat to heat the saturated steam The average temperature difference with the saturated steam becomes large and the saturated steam can be heated more effectively by the combustion gas. As a result, the steam can be heated to a high temperature.

  A further characteristic configuration of the superheated steam generator according to the present invention is that a baffle plate for guiding a flow of saturated steam is provided in the first smoke pipe in the superheated steam generation section.

  According to the above characteristic configuration, the baffle plate that penetrates the first smoke pipe and induces the flow of saturated water vapor is provided in the superheated steam generator. Thereby, as a result of the heat of the combustion gas being transmitted to the baffle plate via the first smoke pipe, the saturated water vapor can also be heated from the surface of the baffle plate. That is, it is possible to effectively heat the saturated steam by expanding the heat transfer area to the saturated steam. Furthermore, the flow of the saturated water vapor can be induced by the baffle plate, and the flow can intersect with the first smoke pipe, and heat exchange on the surface of the first smoke pipe is promoted so that more heat is transferred to the saturated water vapor. As a result, high thermal efficiency can be obtained.

To a still further characterizing feature of the overheated steam generator according to the present invention surrounds the periphery of the first smoke tube constituting the superheated steam generating unit, the closed space to form a closed space to flow through the saturated steam and superheated steam formation A member is provided, and the closed space forming member is thermally insulated from the outer surface of the pressure vessel.

  In the case where the superheated steam generation unit is configured by the first smoke pipe, the surroundings of the first smoke pipe become high-temperature superheated steam (for example, 350 ° C.). The temperature difference from the temperature (° C) increases and the amount of heat dissipation increases accordingly. As a result, heat loss is increased and it is difficult to increase the steam temperature. As a countermeasure for this, for example, it is conceivable to improve the heat insulation performance by increasing the heat insulation thickness of the pressure vessel, but the outer dimensions of the pressure vessel are increased, leading to an increase in size and cost. Therefore, according to the present characteristic configuration, the closed space forming member that is thermally insulated from the outer surface of the pressure vessel is disposed, and the periphery of the first smoke pipe is surrounded by the closed space forming member, so that saturated steam and superheat A closed space through which steam flows is formed. Thereby, it is possible to prevent the superheated steam flowing in the closed space from directly passing to the outer surface of the pressure vessel. A space for allowing a fluid having a temperature lower than that of superheated steam, such as saturated steam (for example, 125 ° C.), to exist between the closed space and the outer surface of the pressure vessel can be present. The temperature difference between the fluid and the outside air can be reduced. Therefore, an increase in the amount of heat radiation can be prevented without increasing the size and cost of the pressure vessel, heat loss can be minimized, and the steam temperature can be increased appropriately. And since the circumference | surroundings of the 1st smoke pipe are covered with the closed space formation member, even when condensed water falls from the upper wall part etc. of a pressure vessel, for example, the condensed water is the 1st smoke pipe and the 1st smoke pipe It is possible to prevent falling to the surroundings, and it is possible to accurately prevent the occurrence of a problem that the steam temperature decreases due to the fall of condensed water.

To a still further characterizing feature of the overheated steam generator according to the present invention, the water level of water received in the pressure vessel, in addition to said furnace tube and said second smoke tube constituting the saturated steam generator, the superheated steam at least a portion of said first smoke tube constituting the generator also as an initial water level be submerged under water, the case where the saturated water vapor by heating water contained in the pressure vessel in the combustion gas begins to occur the configuration of the water level of water received in the pressure vessel, from the initial level, the said furnace tube and said and said superheated steam generating portion and a second smoke pipes submerged under water that constitutes the saturated steam generation unit the first smoke tube is lowered to a reference level to be exposed on the water surface, there the water level of water contained in the pressure vessel to a point that is configured to perform a level control to maintain the reference level.

In this superheated steam generator, since it takes several minutes until the water contained in the pressure vessel boils and begins to generate saturated steam, the first smoke constituting the superheated steam generating unit is required during this period. Saturated water vapor does not flow around the tube . Therefore, it will be in a so-called empty-fired state, which may adversely affect the durability of the superheated steam generator. For example, in order to reduce the temperature of the combustion gas to flow through the first smoke tube constituting the superheated steam generating unit, squeeze the combustion amount of burners, or even to burn the burner to increase the excess air ratio of the burner conceivable, but not enough to prevent overheating of the first smoke tube constituting the superheated steam generating unit.

Therefore, according to this characteristic configuration, first, the water level stored in the pressure vessel is set to the initial water level, and then the water level stored in the pressure vessel is lowered from the initial water level to the reference water level, and the water stored in the pressure vessel is stored. The water level is controlled to maintain the water level at the reference water level. In the initial level, so also it is submerged under water at least a portion of the first smoke tube constituting the superheated steam generating unit, housed in a pressure vessel in the combustion gas flowing through the first smoke tube constituting the superheated steam generating unit It has been that the water is to be heated, to prevent the the boil-dry state, it is possible to properly carry out the overheating prevention of the first smoke tube constituting the superheated steam generating unit.

Here, the first smoke constituting the superheated steam generator is formed by heating the water with the combustion gas while making the water stored in the pressure vessel full, and passing the water through the pressure vessel to maintain the full water state. It is thought that the tube can be prevented from overheating. However, since water is heated with the combustion gas while passing through the pressure vessel, it takes time until the water contained in the pressure vessel is heated with the combustion gas and saturated steam begins to be generated. The time until the superheated steam can be generated after the start of operation of the vessel becomes longer. Moreover, when water is heated with combustion gas while passing through the pressure vessel, hot water may be ejected from the superheated steam outlet that takes out the superheated steam. If used for this, the food to be heated will be damaged. On the other hand, according to the present characteristic configuration, the water contained in the pressure vessel with the combustion gas can be obtained only by setting the water level contained in the pressure vessel to the initial water level without passing water through the pressure vessel. Because it can be heated, the time from the start of operation of the superheated steam generator until it becomes possible to generate superheated steam can be shortened, and hot water can be ejected from the superheated steam outlet that takes out superheated steam. Can also be prevented.

  In this way, when the water stored in the pressure vessel is heated with combustion gas and saturated steam begins to be generated, the water level stored in the pressure vessel is lowered from the initial water level to the reference water level, By maintaining the reference water level, water can be generated by heating water in the saturated water vapor generating section, and superheated steam can be generated by heating the saturated water vapor in the superheated steam generating section.

  In the superheated steam generator according to the present invention, in the water level control, when the water level stored in the pressure vessel is lowered from the initial water level to the reference water level, the combustion gas causes the pressure resistance. The initial water level is generated by heating the water contained in the container to generate saturated water vapor and / or the operation of the drainage means for draining the water contained in the pressure vessel. To lower the water level to the reference water level.

  According to this characteristic configuration, the water level stored in the pressure vessel can be lowered by heating the water contained in the pressure vessel with combustion gas to generate saturated water vapor. Therefore, the water level can be lowered from the initial water level to the reference water level by the generation of the saturated water vapor without adding a new configuration. In addition, when a drainage means for draining the water stored in the pressure vessel is provided, in addition to the generation of saturated water vapor, the drainage means is operated to quickly lower the water level from the initial water level to the reference water level. be able to. Therefore, the time from when the operation of the superheated steam generator is started until the superheated steam can be generated can be shortened as much as possible.

  A further characteristic configuration of the superheated steam generator according to the present invention is such that the closed space forming member is smaller than a saturated water vapor inlet for introducing saturated water vapor into the closed space, and the closed space and the other than the above. A hole is formed to allow water to flow between the internal space of the pressure vessel.

  According to this characteristic configuration, since the hole is formed in the closed space forming member, for example, even if water droplets or the like flow into the closed space, the water is discharged from the closed space to the other internal space of the pressure vessel through the hole. be able to. Moreover, as described in the above characteristic configuration, when the water level stored in the pressure vessel is the initial water level, or when the water level stored in the pressure vessel is lowered from the initial water level to the reference water level, a closed space is formed. By allowing water to flow between the closed space and the other internal space of the pressure vessel through the hole formed in the member, the water level can be adjusted appropriately using the hole.

Longitudinal sectional view of the superheated steam generator according to the first embodiment II-II arrow view of the superheated steam generator of FIG. The outer peripheral wall side baffle plate (a) and the partition plate side baffle plate (b) of the superheated steam generator according to the first embodiment Cross-sectional view of the superheated steam generator according to the second embodiment Vertical section of superheated steam generator according to the reference example VI-VI arrow view of the superheated steam generator of FIG. Longitudinal sectional view of the superheated steam generator according to the third embodiment Longitudinal sectional view of the superheated steam generator according to the third embodiment IX-IX arrow view of the superheated steam generator of FIG.

[First Embodiment]
Hereinafter, an embodiment of a superheated steam generator according to the present invention will be described based on the drawings. FIG. 1 is a vertical cross-sectional view from the side of the superheated steam generator D, and FIG. 2 is a cross-sectional view of the superheated steam generator D (II-II arrow view of the superheated steam generator in FIG. 1). As shown in FIG. 1, the superheated steam generator D includes a horizontal cylindrical pressure-resistant container 1 in which water W is accommodated, and a combustion gas flow that is disposed in the pressure-resistant container 1 and distributes the combustion gas G. It is comprised by the path 2 and the burner B which generate | occur | produces the combustion gas G supplied to the combustion gas flow path 2.

The combustion gas flow path 2 is configured by connecting a furnace tube 2c, a first header 2f, a first smoke pipe 2d, a second header 2g, and a second smoke pipe 2e. As indicated by solid line arrows in FIG. 1, the furnace tube 2 c is configured such that the combustion gas G is supplied to one side of the pressure vessel 1 in the axial direction (left-right direction in FIG. 1) (right side in FIG. The pressure vessel 1 is introduced into the pressure vessel 1 and is distributed toward the other side in the axial direction (left side in FIG. 1, hereinafter referred to as “discharge port side”). The first header 2f guides and distributes the combustion gas G that has passed through the furnace tube 2c to the first smoke pipe 2d with its flow direction turned back. The 1st smoke pipe 2d distribute | circulates the combustion gas G which passed the furnace cylinder 2c toward the inlet side from the discharge port side. The second header 2g guides and distributes the combustion gas G that has passed through the first smoke pipe 2d to the second smoke pipe 2e with its flow direction turned back. The second smoke pipe 2e causes the combustion gas G that has passed through the first smoke pipe 2d to flow from the inlet side toward the outlet side. An exhaust header 3 is provided outside the discharge port side in the axial direction of the pressure vessel 1, and the combustion gas G that has passed through the second smoke pipe 2e is supplied to the exhaust header 3 and discharged to the outside of the pressure vessel 1. ing.
As described above, the combustion gas flow path 2 is configured in a three-pass structure in which the combustion gas G flows three times between the inlet side and the outlet side in the axial direction of the pressure-resistant vessel 1.

  A partition plate 4 that partitions the internal space of the pressure vessel 1 into an upper space and a lower space is provided. The lower space is configured as a saturated steam generator VF that heats the water W to generate saturated steam V, and the upper space that heats the saturated steam V to generate superheated steam S in the upper space. It is configured as. The partition plate 4 does not partition the upper space and the lower space in a sealed state, but includes a portion C that communicates the lower space and the upper space on the inlet side in the axial direction of the pressure vessel 1. Yes. The saturated steam V generated in the saturated steam generating section VF that is the lower space can be supplied to the superheated steam generating section SF that is the upper space through the communicating portion C.

In the saturated water vapor generation part VF, water W is stored up to the reference water level T, and a furnace tube 2c and a second smoke pipe 2e are disposed below the reference water level T. The periphery of the two smoke pipes 2e is a flow path through which water W and saturated water vapor V can freely flow. As shown in FIG. 2, one furnace tube 2c is provided, and a plurality of second smoke tubes 2e are provided at intervals in the circumferential direction of the furnace tube 2c so as to surround the periphery of the one furnace tube 2c. ing.
In the superheated steam generator SF, a plurality of first smoke pipes 2d are provided at intervals, and the periphery of the plurality of first smoke pipes 2d is a flow path through which the saturated steam V and the superheated steam S can flow. ing.
As described above, the partition plate 4 partitions the inside of the pressure-resistant vessel 1 into the saturated steam generation unit VF and the superheated steam generation unit SF, and prevents water droplets from entering the superheated steam generation unit SF.

As shown in FIG. 1, the pressure vessel 1 has a horizontal cylindrical shape, a cylindrical outer peripheral wall 1a, and a pair of opposed outer walls 1b, 1c that block both side surfaces of the cylindrical outer peripheral wall 1a. It consists of and. In addition, a superheated steam outlet 13 for taking out the superheated steam S generated in the pressure vessel 1 is provided above the outer peripheral wall 1a. In addition, a saturated steam outlet 14 for taking out the saturated steam V, a pressure gauge ( A pressure gauge attachment port 15 to which a thermometer (not shown) is attached and a thermometer attachment port 16 to which a thermometer (not shown) is attached are provided. On the other hand, as shown in FIG. 2, below the outer peripheral wall 1a, the water supply port 11 for supplying water W for generating saturated water vapor V in the pressure vessel 1 and the water level in the pressure vessel 1 are detected and displayed. A water level gauge connection port 12 to which a water level gauge (not shown) is connected is provided. The water level gauge is provided in the pressure vessel 1 near the superheated steam outlet 13 so that the reference water level T can be detected. In addition, on-off valves (not shown) are attached to the superheated steam outlet 13 and the saturated steam outlet 14.
The pair of outer walls 1b and 1c are provided with an inlet-side outer wall 1b provided with a combustion gas inlet 2a for introducing the combustion gas G generated by the combustion in the burner B into the combustion gas flow path 2, and the combustion. It is comprised by the discharge port side outer side wall 1c provided with the combustion gas discharge port 2b which discharges | emits the combustion gas G from the gas flow path 2. As shown in FIG. The pressure vessel 1 is mounted on the pressure vessel holder 10. In addition, the pressure vessel 1 is provided with an overpressure relief valve (not shown), a burner B attachment mechanism for generating combustion gas G, and the like.

  A burner B is provided on the inlet side outer side wall 1 b of the pressure vessel 1, and combustion gas G is generated by combustion of the burner B, and the combustion gas G is introduced into the combustion gas flow path 2. Yes. The burner B can be automatically ignited by an ignition device, and can be adjusted by a thermal power adjusting device after ignition.

Further, as shown in FIG. 1, the combustion gas flow path 2 provided in the pressure vessel 1 communicates in the order of the furnace tube 2c, the first header 2f, the first smoke pipe 2d, the second header 2g, and the second smoke pipe 2e. Connected and configured in a state. The furnace tube 2c is connected to and supported by an inlet-side outer wall 1b located on the axial inlet side of the pressure vessel 1, and a combustion gas inlet 2a, which is an inlet for the combustion gas G, is connected to the furnace tube 2c. Form. The second smoke pipe 2e is connected to and supported by the discharge-side-side outer wall 1c on the discharge port side in the axial direction of the pressure-resistant vessel 1, and is connected to the discharge port of the combustion gas G from the second smoke pipe 2e. A certain combustion gas discharge port 2b is formed. As a result, the combustion gas G introduced from the combustion gas introduction port 2a provided in the inlet side outer wall 1b of the pressure vessel 1 flows through the combustion gas passage 2 and is led to the combustion gas discharge port 2b to be discharged. Is done.
The first header 2f is supported from the furnace tube 2c in the vicinity of the end portion on the discharge port side of the furnace tube 2c, and the second header 2g is formed by the second smoke pipe 2e in the vicinity of the end portion on the introduction port side of the furnace tube 2c. It is supported. And the 1st smoke pipe 2d is connected and supported between the 1st header 2f and the 2nd header 2g, and the combustion gas flow path 2 is comprised.

  The furnace tube 2c is configured by a single circular tube, and the central axis of the furnace tube 2c is located below the central axis of the pressure vessel 1 while providing the central axis of the furnace tube 2c along the axial direction of the pressure vessel 1. It is arranged to do. The furnace tube 2 c is connected to and supported by the inlet side outer wall 1 b at the end of the pressure vessel 1 on the inlet side, and forms a combustion gas inlet 2 a. Further, the furnace tube 2c extends to the discharge port side while slidably passing through the second header 2g provided on the introduction port side, and is connected to the first header 2f. Thereby, the combustion gas G introduced from the combustion gas introduction port 2a circulates from the introduction port side of the pressure-resistant vessel 1 toward the discharge port side, and the combustion gas G introduced from the combustion gas introduction port 2a is changed to the first. The header 2f can be distributed.

The first header 2f is provided on the discharge port side inside the pressure vessel 1 and has a first header outer portion 2fa that is a cylindrical outer portion along the inner surface of the outer peripheral wall 1a of the pressure vessel 1, and the first header outer portion 2fa. The first header discharge side surface 2fb provided at the end on the inlet side outer wall 1b side which is one end of the first header and the first header discharge provided on the end portion on the discharge port side outer wall 1c side which is the other end. It is formed in a hollow cylindrical shape with the outlet side surface 2fc.
A furnace tube 2c is connected to a lower portion of the first header inlet side surface 2fb in a communicating state. On the other hand, six first smoke pipes 2d along the inner surface of the outer peripheral wall 1a of the pressure vessel 1 are connected to the upper portion of the first header inlet side surface 2fb in a communicating state. Thus, the 1st header 2f is comprised so that the guidance distribution which branches and introduces the combustion gas G which flowed in from the furnace cylinder 2c to the six 1st smoke pipes 2d is possible.

Further, the first header discharge port side surface 2fc of the first header 2f is disposed in a non-contact state with an interval in the axial direction of the pressure resistant container 1 between the inner wall of the discharge port side outer side wall 1c of the pressure resistant container 1. Has been. As described above, the gap is provided between the first header discharge port side surface 2fc and the discharge port side outer wall 1c, and the first header discharge port side surface 2fc is cooled by the water W existing in the gap. Heat transfer from the discharge port side surface 2fc to the discharge port side outer wall 1c can be suppressed, and the temperature rise of the discharge port side outer wall 1c can be suppressed. As a result, the water W in the pressure vessel 1 is heated, and the saturated water vapor V can be generated more effectively. Further, it is possible to eliminate the occurrence of thermal stress between the first header 2f and the discharge port side outer wall 1c, and to prevent the discharge port side outer wall 1c and the first header 2f from being distorted, cracked, broken or the like. .
Further, the first header 2f is provided with twelve second smoke tube through holes 2fd through which twelve second smoke tubes 2e are slidably penetrated around the connection portion of the furnace tube 2c. Thus, as a configuration that allows thermal expansion that occurs in the second smoke pipe 2e that passes through the first header 2f, generation of thermal stress between the first header 2f and the second smoke pipe 2e is eliminated, and the first header 2f In addition, it is possible to prevent distortion, cracks, breakage, and the like from occurring in the second smoke pipe 2e.

  As shown in FIG. 2, six first smoke tubes 2d are provided along the upper inner surface of the outer peripheral wall 1a of the pressure vessel 1 above the furnace tube 2c. Returning to FIG. 1, these six first smoke pipes 2d connect the first smoke pipe 2d to the first header inlet side surface 2fb and the second header outlet side surface 2gc in communication. Thereby, the combustion gas G introduced into the first smoke pipe 2d from the first header 2f circulates from the discharge port side to the introduction port side of the pressure-resistant vessel 1, and flows into the second header 2g.

  The 2nd header 2g is provided in the inlet side inside the pressure vessel 1, and the 2nd header outer periphery 2ga which is a cylindrical outer peripheral part along the inner surface of the outer peripheral wall 1a of the pressure vessel 1, and the 2nd header outer periphery 2ga, the second header introduction side surface 2gb provided at the end on the introduction port side outer wall 1b side, which is one end of 2ga, and the second header provided on the end portion on the discharge port side outer wall 1c side, which is the other end. It is formed in a hollow cylindrical shape with the discharge port side surface 2gc. The six first smoke pipes 2d are connected in communication with the upper portion of the second header discharge port side surface 2gc. On the other hand, twelve second smoke pipes 2e provided along the outer peripheral wall of the furnace tube 2c are connected to the lower portion of the second header discharge port side surface 2gc in a communicating state. As described above, the second header 2g allows the guide circulation in which the combustion gas G flowing in from the six first smoke pipes 2d is merged and branched again to the twelve second smoke pipes 2e. Composed.

  A furnace tube through hole 2gd through which the furnace tube 2c slidably passes is provided at a lower portion of the second header 2g. As a result, expansion and contraction based on the temperature change of the furnace tube 2c penetrating the second header 2g is allowed, generation of thermal stress between the second header 2g and the furnace tube 2c is eliminated, and the second header 2g In addition, it is possible to prevent distortion, cracks, breakage, and the like from occurring in the furnace tube 2c.

  Furthermore, the second header inlet side surface 2gb is disposed between the inner wall of the inlet side outer wall 1b of the pressure vessel 1 with an interval in the axial direction of the pressure vessel 1. Thereby, as a configuration that allows thermal expansion that occurs in the second smoke pipe 2e that penetrates the first header 2f, generation of thermal stress that occurs between the second header 2g and the inlet-side outer wall 1b is eliminated, It is possible to prevent the second header 2g and the inlet-side outer wall 1b from being distorted, cracked, broken or the like.

As shown in FIG. 2, the second smoke pipe 2e is provided with 12 cylindrical pipes at equal intervals along the outer peripheral surface of the furnace tube 2c. Thereby, the 2nd header 2g and the combustion gas discharge port 2b formed in the discharge port side outer side wall 1c of the pressure-resistant container 1 are connected in the communication state.
An end of the second smoke pipe 2e on the inlet side of the pressure vessel 1 is connected in communication with an upper portion of the second header outlet side surface 2gc. Combusting from the second header discharge port side surface 2gc to the discharge port side of the pressure vessel 1 and passing through the second smoke pipe through hole 2fd of the first header 2f and connected to the discharge port side outer wall 1c of the pressure vessel 1 A gas discharge port 2b is formed. Thereby, the combustion gas G introduced into the second smoke pipe 2e from the second header 2g flows from the inlet side of the pressure-resistant vessel 1 toward the outlet side to the combustion gas outlet 2b.

  Combustion gases G discharged from the respective combustion gas discharge ports 2b of the 12 second smoke pipes 2e are merged by the exhaust header 3 provided on the outer surface of the discharge port side outer wall 1c of the pressure resistant vessel 1, and the exhaust header 3 It exhausts from the exhaust port 3a installed in the upper part.

As shown in FIGS. 1 and 2, the first smoke pipe 2 d is disposed on the surface of the water W contained in the pressure-resistant container 1, and generates the superheated steam S by heating the saturated steam V with the combustion gas G. The superheated steam generation unit SF is configured, and the furnace tube 2c and the second smoke pipe 2e are disposed below the surface of the water W accommodated in the pressure resistant vessel 1, and the water W is heated with the combustion gas G to be saturated steam. A saturated water vapor generation unit VF that generates V is configured.
In addition, water W is consumed due to the generation of saturated water vapor V, and the water level in the pressure-resistant vessel 1 is lowered. However, when the water level is detected by a water level gauge (not shown) and the water level falls below the reference water level T, The water W pressurized by a pressure pump (not shown) is configured to be supplied into the pressure vessel 1 from a water supply port 11 provided below the outer peripheral wall 1a. The supplied water W may be subjected to water softening treatment by a water softener (not shown). Thereby, it is possible to prevent the scale component from being deposited in the pressure vessel 1.

  As described above, the partition plate 4 divides the inside of the pressure resistant vessel 1 into the saturated steam generating portion VF and the superheated steam generating portion SF, and the end on the discharge port side in the axial direction of the pressure resistant vessel 1 is the discharge port. It is connected and supported by the side outer wall 1c, and the end portion on the introduction port side is connected and supported by the second header discharge port side surface 2gc. In the superheated steam generator SF, the superheated steam S is generated by heating the saturated steam V with the combustion gas G in the first smoke pipe 2d. As shown by the solid line arrow in FIG. The flow direction of the combustion gas G in the smoke pipe 2d is from the discharge port side to the introduction port side in the axial direction of the pressure resistant vessel 1, and the flow direction of the saturated steam V is the pressure resistance as shown by the dotted arrow in FIG. From the inlet side to the outlet side in the axial direction of the container 1. Thereby, it is possible to generate the superheated steam S by performing heat exchange in the superheated steam generation unit SF with the flow of the saturated steam V and the flow of the combustion gas G in the first smoke pipe 2d as an opposing flow.

Further, in the superheated steam generation section SF, a baffle plate 5 is provided that penetrates through the first smoke pipe 2d and is installed substantially at right angles to the flow of the saturated steam V. The baffle plate 5 is joined to the inner side of the outer peripheral wall 1a of the pressure-resistant container 1, so that the outer peripheral wall side baffle plate 5a (FIG. 3A) having a flow path V2 of saturated water vapor V on the partition plate 4 side, and the partition plate 4, the partition plate side baffle plate 5 b (FIG. 3B) having the flow path V 3 on the outer peripheral wall 1 a side of the pressure vessel 1 is joined. And the outer peripheral wall side baffle plate 5a and the partition plate side baffle plate 5b are alternately provided along the axial direction of the 1st smoke pipe 2d.
In addition, the outer peripheral wall side baffle plate 5a is fixedly provided on the inner side of the first smoke pipe 2d and the outer peripheral wall 1a of the pressure vessel 1, but the baffle plate 5 is configured to be very thin, and spot welding, etc. Are partially connected. Therefore, the thermal expansion of the first smoke pipe 2d does not generate a thermal stress with the first smoke pipe 2d.

  Next, the temperature change of the combustion gas G from when the combustion gas G generated by the combustion of the burner B is introduced at the combustion gas introduction port 2a until it is exhausted from the exhaust port 3a will be described. A high-temperature combustion gas G (for example, 1800 ° C.) generated by the combustion of the burner B is first introduced into the furnace tube 2c from the combustion gas inlet 2a, and the water W in the pressure vessel 1 is passed through the outer peripheral wall of the furnace tube 2c. And heat exchange. After that, it is split and introduced into the six first smoke pipes 2d through the first header 2f at a relatively high temperature (for example, 1000 ° C.), and exchanges heat with the saturated steam V through the outer peripheral wall of the first smoke pipe 2d. Superheated steam S (for example, 350 ° C.) is generated. Thereafter, the combustion gas G is introduced into the second header 2g and merges. When the combustion gas G flows out from the second header 2g, the combustion gas G is divided again into the 12 second smoke pipes 2e provided below the surface of the water W. It is introduced at a low temperature (eg 760 ° C.). And after exchanging heat with water W through the outer peripheral wall of the 2nd smoke pipe 2e, low-temperature combustion gas G (for example, 220 degreeC) is discharged | emitted from the 12 combustion gas discharge ports 2b, and merges in the exhaust header 3. It is discharged from the exhaust port 3a.

  The flow from when the water W is supplied into the pressure resistant container 1 through the water supply port 11 until the superheated steam S is taken out from the superheated steam outlet 13 will be described. First, the water W is softened and then pressurized by a pressure pump (not shown) and filled in the pressure vessel 1 so as to reach the reference water level T from the water supply port 11 provided at the lower portion of the pressure vessel 1. The Then, it is heated and evaporated by the furnace tube 2c and the second smoke pipe 2e to become the saturated steam V, rises to the upper part of the pressure vessel 1, and after the water droplets are separated, the superheated steam generator SF from the saturated steam inlet V1. To be introduced. Then, in the superheated steam generation unit SF, heat exchange is performed in a state where the flow of the saturated steam V flowing inside the superheated steam generation unit SF and the combustion gas G in the first smoke pipe 2d is a counter flow, and the saturated steam V is heated to become superheated steam S and is taken out from the superheated steam outlet 13.

  In the superheated steam generation part SF, a plurality of baffle plates 5 arranged substantially perpendicular to the axial direction of the second smoke pipe 2e are provided so as to penetrate the first smoke pipe 2d. By attaching a plurality of baffle plates 5 to the outer peripheral wall of the first smoke pipe 2d, not only can the heat transfer area to the saturated steam V flowing through the superheated steam generator SF be expanded, but also when the flow of the saturated steam V is induced By crossing the first smoke pipe 2d while generating a turbulent flow, heat exchange between the saturated steam V and the combustion gas G is promoted, and the saturated steam V can be effectively heated. Furthermore, by making the flow of the saturated steam V flowing through the superheated steam generation section SF and the flow of the combustion gas G in the first smoke pipe 2d counterflow, the temperature of the combustion gas G to be heat exchanged and the temperature of the saturated steam V And the average temperature difference becomes larger. As a result, the heat transfer rate is improved, and as a result, higher thermal efficiency can be obtained. Incidentally, in the superheated steam generator D in the present embodiment, a thermal efficiency of about 80% can be obtained on the basis of the higher heating value (HHV).

[Second Embodiment]
FIG. 4 is a cross-sectional view of the superheated steam generator D according to the second embodiment of the present invention. The difference of the second embodiment from the first embodiment is that the two second smoke pipes 2e above the furnace tube 2c are moved. Other configurations are substantially the same as those in the first embodiment. In the first embodiment, twelve second smoke pipes 2e are provided at equal intervals around the outer peripheral wall of the furnace tube 2c. In the second embodiment, as shown in FIG. 4, the outer periphery of the furnace tube 2c is provided. Ten second smoke pipes 2e are arranged at equal intervals along the outer periphery excluding the upper part, and are located on the uppermost side of the second smoke pipe 2e provided along the outer periphery excluding the outer peripheral upper part of the furnace tube 2c in a sectional view. The arrangement positions of the two left and right second smoke pipes 2e are changed. That is, the arrangement positions of the two left and right second smoke pipes 2e are set to be the same in height in the vertical direction as the uppermost one of the other ten second smoke pipes 2e. Thereby, all the 12 second smoke pipes 2e can be appropriately arranged below the reference water level T.

  As a result, particularly when the superheated steam generator D is downsized, it is necessary to lower the reference water level T, while maintaining high thermal efficiency without reducing the number of second smoke pipes 2e. The water level T can be lowered.

[ Reference example ]
FIG. 5 is a longitudinal sectional view of the superheated steam generator D in the reference example . FIG. 6 is a cross-sectional view of the superheated steam generator D in the reference example (a view taken along arrows VI-VI of the superheated steam generator D of FIG. 5). The difference from the first embodiment in the present reference example is that the positions where the first smoke pipe 2d and the second smoke pipe 2e of the combustion gas flow path 2 are arranged in relation to the reference water level T in the pressure resistant vessel 1 are different. Is a point. That is, in 1st Embodiment, although the 1st smoke pipe 2d is arrange | positioned above the reference | standard water level T in the pressure-resistant container 1, and the 2nd smoke pipe 2e is arrange | positioned below the reference | standard water level T, this reference example is comprised. The first smoke pipe 2d is arranged below the reference water level T, and the second smoke pipe 2e is arranged above the reference water level T.

Therefore, in the present reference example , the first smoke pipe 2d and the furnace tube 2c arranged below the reference water level T constitute the saturated water vapor generating part VF, and the second smoke pipe 2e arranged above the reference water level T is overheated. The steam generation unit SF is configured.
In the saturated water vapor generation part VF, water W is stored up to the reference water level T, and a furnace tube 2c and a first smoke pipe 2d are disposed below the reference water level T. A passage around which the water W and the saturated water vapor V can freely flow is formed around the 1 smoke pipe 2d. As shown in FIG. 6, one furnace tube 2c is provided, and a plurality of first smoke tubes 2d are provided at intervals in the circumferential direction of the furnace tube 2c so as to surround the periphery of the one furnace tube 2c. ing.
The saturated steam generation section VF is provided with a plurality of second smoke pipes 2e at intervals, and the periphery of the plurality of second smoke pipes 2e is a flow path through which the saturated steam V and the superheated steam S can flow. ing. As a result, the water W in the pressure vessel 1 is heated by the furnace tube 2c and the first smoke pipe 2d in the saturated water vapor generation unit VF to evaporate to become the saturated water vapor V and rises to the upper portion of the pressure vessel 1, Is separated and then introduced into the superheated steam generator SF from the saturated steam inlet V1. Then, in the superheated steam generation section SF, heat exchange is performed in a state where the flow of the saturated steam V and the combustion gas G in the second smoke pipe 2e is a counter flow, the saturated steam V is heated, and the superheated steam S and And is taken out from the superheated steam outlet 13.

[ Third Embodiment]
7 and 8 are longitudinal sectional views of the superheated steam generator D in the third embodiment of the present invention. FIG. 9 is a cross-sectional view of the superheated steam generator D in the third embodiment (an IX-IX arrow view of the superheated steam generator D of FIG. 8). In the third embodiment, in the first embodiment described above, a structure for forming a closed space K surrounding the first smoke pipe 2d constituting the superheated steam generation unit SF is added, and water stored in the pressure resistant vessel 1 is added. Added a configuration to adjust the water level. FIG. 7 shows a case where the water level stored in the pressure vessel 1 is adjusted to the initial water level T1, and FIG. 8 shows a case where the water level stored in the pressure vessel 1 is adjusted to the reference water level T. Show.

As shown in FIGS. 8 and 9, the first smoke pipe 2 d is accommodated in the pressure resistant container 1 in the state where the water level accommodated in the pressure resistant container 1 is adjusted to the reference water level T as in the first embodiment. The superheated steam generator SF is disposed on the water surface of the water W and generates the superheated steam S by heating the saturated steam V with the combustion gas G. The furnace tube 2c and the second smoke pipe 2e are composed of a pressure vessel. 1, a saturated water vapor generation unit VF that is disposed under the surface of the water W accommodated in 1 and generates water vapor V by heating the water W with the combustion gas G is configured.
Since high-temperature superheated steam (for example, 350 ° C.) flows around the first smoke pipe 2d, if the superheated steam directly passes to the outer surface of the pressure-resistant vessel 1, the temperature difference from the outside air becomes large and is released accordingly. The amount of heat increases. As a result, heat loss increases and it becomes difficult to increase the steam temperature. Therefore, in the third embodiment, the closed space K that surrounds the first smoke pipe 2d is formed by the closed space forming member 17 that is thermally shielded from the outer surface of the pressure-resistant vessel 1, and the inside of the closed space K is Saturated steam V and superheated steam S are passed through.

In the third embodiment, instead of the partition plate 4 in the first embodiment, a closed space K that surrounds the periphery of the first smoke pipe 2d constituting the superheated steam generator SF and allows the saturated steam V and the superheated steam S to flow therethrough. The closed space forming member 17 is formed. The closed space forming member 17 includes a cylindrical member 17a that surrounds the entire circumference of the first smoke pipe 2d, and a first block that closes the axial discharge port side of the pressure-resistant container 1 in the internal space of the cylindrical member 17a. The header 2f is composed of a second header 2g that closes the axial inlet side of the pressure-resistant container 1 in the internal space of the cylindrical member 17a. The cylindrical member 17a is disposed in a non-contact state where it does not come into contact with the outer surface of the pressure-resistant container 1, and both ends of the cylindrical member 17a in the axial direction of the pressure-resistant container 1 are not in contact with the outer surface of the pressure-resistant container 1. By connecting to the first header 2 f and the second header 2 g disposed in a state, the closed space forming member 17 is thermally insulated from the outer surface of the pressure-resistant container 1. The first smoke pipe 2d is provided with a plurality (for example, 13 as shown in FIG. 9) arranged in the vertical and horizontal directions of the pressure-resistant container 1, and the cylindrical member 17a is provided with the plurality of first smoke pipes 2d. It is provided so as to surround all surroundings. The discharge port side of the cylindrical member 17a is connected to the first header 2f and closed, and the introduction port side of the cylindrical member 17a is connected to the second header 2g and closed. Thereby, the closed space K surrounding the circumference | surroundings of the some 1st smoke pipe 2d is formed of the closed space formation member 17 comprised from the cylindrical member 17a, the 1st header 2f, and the 2nd header 2g. Incidentally, on the inlet side in the axial direction of the pressure vessel 1, similarly to the first embodiment, a lower space where the furnace tube 2 c and the second smoke pipe 2 e are located and an upper space where the first smoke pipe 2 d is located. A communicating part C is provided.

  A saturated water vapor inlet V1 for introducing saturated water vapor V into the closed space K is formed on the upper side of the cylindrical member 17a, and the saturated water vapor V generated by the saturated water vapor generator VF is introduced into the saturated water vapor. It is configured to be supplied into the closed space K through the mouth V1. Thus, the effect of brackish water separation is accelerated | stimulated by making the inlet of the saturated water vapor | steam V into the closed space K into the upper side of the cylindrical member 17a. Saturated steam V is passed through the closed space K, and the saturated steam V is heated by the combustion gas G in the first smoke pipe 2d to generate superheated steam S, and the generated superheated steam S is It flows through the closed space K. The superheated steam outlet 13 is connected in communication in the closed space K, and the superheated steam S in the closed space K is taken out through the superheated steam outlet 13.

  In this way, it is possible to prevent the superheated steam S flowing in the closed space K from being directly communicated with the outer surface of the pressure-resistant vessel 1, and between the closed space K and the outer surface of the pressure-resistant vessel 1. In addition, since there can be a space through which the saturated steam V (for example, 135 ° C.) having a temperature lower than that of the superheated steam S, the temperature difference between the low-temperature saturated steam V fluid and the outside air can be reduced (for example, superheated) Compared to the temperature difference between steam and outside air, it can be reduced by about 100 ° C.). Therefore, an increase in the amount of heat radiation can be prevented, heat loss can be minimized, and the steam temperature can be suitably increased. Moreover, since the periphery of the first smoke pipe 2d is covered with the closed space forming member 17, for example, even when the condensed water falls from the upper wall portion or the like of the pressure-resistant container 1, the condensed water remains in the first smoke pipe 2d or It is possible to prevent falling around the first smoke pipe 2d, and it is possible to accurately prevent the occurrence of the problem that the steam temperature decreases due to the fall of the condensed water.

  On the lower side of the cylindrical member 17a, a hole 18 that is smaller than the saturated water vapor inlet V1 and that allows water to flow between the closed space K and the other internal space of the pressure vessel 1 is formed. Has been. The hole 18 is formed in the tubular member 17a at a total of two locations, one location on the discharge port side in the axial direction of the pressure vessel 1 and one location on the introduction port side in the axial direction of the pressure vessel 1. The hole 18 is, for example, about 1/10 of the opening area of the saturated water vapor inlet V1, and is formed in a circular shape having a diameter of 2 mm.

In this 3rd Embodiment, the water level control part H which adjusts the water level of the water W accommodated in the pressure | voltage resistant container 1 is provided. First, as shown in FIG. 7, the water level control unit H sets the water level of the water W stored in the pressure-resistant container 1 to the initial water level T1, and heats the water W stored in the pressure-resistant container 1 with the combustion gas G. When the saturated water vapor V starts to be generated, the water level of the water W stored in the pressure vessel 1 is lowered from the initial water level T1 to the reference water level T and stored in the pressure vessel 1 so as to shift from FIG. 7 to FIG. The water level is controlled to maintain the water level at the reference water level T.

As shown in FIG. 7, the initial water level T1 includes at least a part of the first smoke pipe 2d constituting the superheated steam generation part SF in addition to the furnace tube 2c and the second smoke pipe 2e constituting the saturated steam generation part VF. The water level is set to be submerged below. That is, it is set at a position above the first smoke pipe 2d so that the entire first smoke pipe 2d is located below the water surface.
As shown in FIG. 8, the reference water level T is such that the furnace tube 2c and the second smoke pipe 2e constituting the saturated steam generation part VF are submerged below the water surface, and the first smoke pipe 2d constituting the superheated steam generation part SF is placed on the water surface. The water level is set to be exposed above. That is, as described in the first embodiment, the first smoke pipe 2d and the second smoke pipe 2e are arranged so that the furnace tube 2c and the second smoke pipe 2e are located below the water surface and the first smoke pipe 2d is located above the water surface. Is set to a position between.

In the pressure vessel 1, the first water level sensor 19 that detects that the water level of the water W stored in the pressure vessel 1 is the initial water level T 1, and the water level of the water W stored in the pressure vessel 1 is the reference water level T. The second water level sensor 20 for detecting this is provided, and detection information of the first and second water level sensors 19 and 20 is input to the water level control unit H. In the superheated steam generator D in the third embodiment, a water supply pump P for supplying water W to the pressure resistant container 1 is provided, and a drain valve 21 (drainage) for draining the water W accommodated in the pressure resistant container 1 is provided. Corresponding to the means). The water level control unit H is configured to perform water level control by controlling the operation of the water supply pump P and the opening and closing of the drain valve 21 based on the detection information of the first and second water level sensors 19 and 20. ing.

  The water level control unit H is configured to be able to raise the water level of the water W stored in the pressure vessel 1 by operating the water supply pump P to supply the water W into the pressure vessel 1 through the water supply port 11. . In addition, the water level control unit H is configured to drain the water W stored in the pressure-resistant container 1 by opening the drain valve 21 so that the water level of the water W stored in the pressure-resistant container 1 can be lowered. ing. And about the fall of the water level of the water W accommodated in the pressure | voltage resistant container 1, heating the water W accommodated in the pressure | voltage resistant container 1 with the combustion gas G in the combustion gas flow path 2, and generating saturated water vapor | steam V However, the water level of the water W accommodated in the pressure vessel 1 can be lowered.

  As described above, since the two holes 18 are formed on the lower side of the cylindrical member 17 a, the holes 18 provide a space between the closed space K and the other internal space of the pressure vessel 1. Water W is allowed to flow. As a result, at the initial water level T1, as shown in FIG. 7, as the water level of the water W stored in the pressure vessel 1 rises, the water W flows through the hole 18 into the closed space K. K is also located below the water surface. Conversely, at the reference water level T, as shown in FIG. 8, as the water level of the water W stored in the pressure vessel 1 decreases, the water W is discharged from the closed space K through the hole 18, and the closed space K becomes It will be exposed on the water surface.

The operation when operating the superheated steam generator D in the fourth embodiment will be described.
When starting the operation of the superheated steam generator D, the water level control unit H first turns on the water supply pump P so that the first water level sensor 19 detects the initial water level T1, as shown in FIG. Operate to adjust the water level of the water W stored in the pressure vessel 1 to the initial water level T1. Then, the combustion of the burner B is started, and the combustion gas G generated by the combustion of the burner B is passed through the combustion gas flow path 2. At the initial water level T1, as shown in FIG. 7, the furnace tube 2c, the first smoke pipe 2d, and the second smoke pipe 2e in the combustion gas flow path 2 are located below the water surface. 2d and the combustion gas G flowing through the second smoke pipe 2e heats the water W stored in the pressure-resistant vessel 1 to generate saturated water vapor V.

  As described above, when the water W stored in the pressure vessel 1 boils and the saturated water vapor V starts to be generated, the water level of the water W stored in the pressure vessel 1 is reduced due to the generation of the saturated water vapor V. The first water level sensor 19 detects a drop in water level from the initial water level T1. As a result, the water level control unit H uses the detection information of the first water level sensor 19 as the combustion gas G to convert the water W stored in the pressure vessel 1 with the initial water level T1 as the water level of the water W stored in the pressure vessel 1. It can be determined that the saturated water vapor V has started to be generated by heating. When the water level control unit H determines that the saturated water vapor V has started to be generated, in addition to lowering the water level due to the generation of the saturated water vapor V, the water level control unit H opens the drain valve 21 and shifts from FIG. 7 to FIG. Therefore, the water level of the water W stored in the pressure vessel 1 is lowered from the initial water level T1 to the reference water level T so that the water level of the water W stored in the pressure vessel 1 is maintained at the reference water level T. Since the second water level sensor 20 can detect that the water level of the water W stored in the pressure vessel 1 is the reference water level T, the water level control unit H uses the second water level sensor 20 to detect the reference water level T. The drain valve 21 is kept open until the second water level sensor 20 detects the reference water level T, and the drain valve 21 is closed.

Here, with respect to the determination that the saturated water vapor V has started to be generated with the water level of the water W stored in the pressure vessel 1 as the initial water level T1, for example, a pressure sensor for detecting the pressure of the pressure vessel 1 is provided. When it is detected that the pressure in the pressure vessel 1 has increased, it can be determined that the saturated water vapor V has started to be generated. Further, a temperature sensor for detecting the temperature of the pressure vessel 1 is provided, and when it is detected that the temperature detected by the temperature sensor has reached the boiling point, it can be determined that the saturated water vapor V has started to be generated.
As described above, when the water level of the water W stored in the pressure vessel 1 is lowered from the initial water level T1 to the reference water level T, the water level is lowered by the generation of the saturated water vapor V and the water level is lowered by opening the drain valve 21. The water level is lowered from the initial water level T1 to the reference water level T. For example, the water level is lowered from the initial water level T1 to the reference water level T only by lowering the water level due to the generation of saturated steam V or only by lowering the water level by opening the drain valve 21. It can also be reduced.

  When the water level of the water W stored in the pressure vessel 1 is lowered from the initial water level T1 to the reference water level T, as shown in FIG. 8, the furnace tube 2c and the second smoke pipe 2e in the combustion gas flow path 2 are below the water surface. Therefore, the combustion gas G flowing through the furnace tube 2c and the second smoke pipe 2e heats the water W stored in the pressure-resistant vessel 1 to generate saturated steam V. Since the water level of the water W stored in the pressure vessel 1 is reduced by the generation of the saturated water vapor V, the water level control unit H operates the water supply pump P so that the second water level sensor 20 detects the reference water level T. Thus, the water level of the water W stored in the pressure vessel 1 is maintained at the reference water level T. The generated saturated water vapor V flows from the lower space to the upper space through the portion C that communicates the lower space and the upper space on the inlet port side in the axial direction of the pressure vessel 1, and above the cylindrical member 17 a. It is circulated in the closed space K through the saturated water vapor inlet V1 formed on the side. In the closed space K, the combustion gas G flowing through the first smoke pipe 2d heats the saturated steam V to generate superheated steam S, and the generated superheated steam S is taken out from the superheated steam outlet 13. .

  In this way, when the operation of the superheated steam generator D is started, first, the water level of the water W stored in the pressure-resistant vessel 1 is set to the initial water level T1, and then the water level of the water W stored in the pressure-resistant vessel 1 is changed. By performing water level control that lowers the initial water level T1 to the reference water level T and maintains the water level of the water W stored in the pressure-resistant vessel 1 at the reference water level T, the first smoke pipe 2d is prevented from being in an empty state. In addition, it is possible to appropriately prevent overheating of the first smoke pipe 2d. Moreover, the water W stored in the pressure vessel 1 is heated by the combustion gas G without passing water through the pressure vessel 1 only by setting the water level of the water W stored in the pressure vessel 1 to the initial water level T1. Therefore, it is possible to shorten the time from the start of the operation of the superheated steam generator D until the superheated steam S can be generated, and hot water from the superheated steam outlet 13 or the like for taking out the superheated steam S. It can also prevent ejection.

[Another embodiment]
(A) In the above embodiment, the pressure vessel 1 is configured by attaching the flat inlet-side outer wall 1b and the outlet-side outer wall 1c to both ends of the pressure vessel 1, but the pressure vessel is not limited thereto. When the pressure in 1 is high, the pressure vessel 1 may be configured by attaching the inlet side outer wall 1b and the outlet side outer wall 1c formed in a hemispherical shape (so-called end plate shape).

(B) In the above embodiment, the burner B for generating the combustion gas G is provided on the inlet side outer side wall 1b of the pressure vessel 1, but this is not restrictive, and the burner is provided inside the furnace tube 2c. It may be installed.

(C) In the above embodiment, the outer peripheral wall 1a, the inlet side outer wall 1b, and the outlet side outer wall 1c of the pressure vessel 1 are not heat-insulated with a heat insulating material. A heat insulating material may be attached to.

(D) In the above-described embodiment, the flow of the saturated steam V flowing through the superheated steam generation unit SF and the flow of the combustion gas G are opposed to each other. It is good also as a parallel flow which makes the flow of the combustion gas G with the flow the same direction.

(E) In the above embodiment, the burner B is provided on the inlet side outer side wall 1b of the pressure vessel 1, and the combustion gas G generated by the combustion of the burner B is introduced into the combustion gas inlet 2a. Not limited to this, the combustion gas G generator may be provided separately, and the combustion gas G may be introduced into the combustion gas inlet 2a.

(F) In the third embodiment, as in the first embodiment described with reference to FIGS. 1 and 2, the superheated steam generator SF is configured by the first smoke pipe 2d, and the furnace tube 2c and the second In the superheated steam generator D, in which the saturated steam generating unit VF is configured by the smoke pipe 2e, a configuration is formed in which the closed space K is formed by the closed space forming member 17 and the water level of the water W stored in the pressure vessel 1 is adjusted. An example is shown. Instead, as in the reference example described with reference to FIGS. 5 and 6, the second smoke pipe 2e constitutes the superheated steam generation section SF, and the furnace tube 2c and the first smoke pipe 2d generate saturated steam. In the superheated steam generator D constituting the portion VF, the closed space forming member 17 forms the closed space K, and the configuration for adjusting the water level of the water W stored in the pressure resistant vessel 1 can be additionally implemented. .

(G) In the third embodiment, the water level control unit H controls the operation of the water supply pump P so that the water level of the water W stored in the pressure vessel 1 is set to the initial water level T1. The water supply pump P is operated by manual operation, and the water level of the water W stored in the pressure vessel 1 can be set to the initial water level T1.

  As described above, it is possible to provide a superheated steam generator that can effectively utilize the residual heat of the combustion gas with a piping structure that can suppress thermal stress generated by heating with the combustion gas without causing clogging of the piping.

DESCRIPTION OF SYMBOLS 1 Pressure-resistant container 2c Furnace cylinder 2d 1st smoke pipe 2e 2nd smoke pipe 2f 1st header 2g 2nd header 4 Partition plate 5 Baffle plate 17 Closed space formation member 18 Hole 21 Drain valve (drainage means)
B Burner D Superheated steam generator G Combustion gas K Closed space S Superheated steam SF Superheated steam generating part T Reference water level T1 Initial water level V Saturated steam VF Saturated steam generating part W Water

Claims (8)

This is a superheated steam generator that heats water with combustion gas generated by combustion of a burner to generate saturated steam, and further heats saturated steam with the combustion gas after heating the water to generate superheated steam. And
The cylindrical pressure vessel that contains water is disposed below the surface of the contained water, and combustion gas is introduced into the inside of the pressure vessel from one side in the axial direction of the pressure vessel. A furnace tube that circulates toward the side, a first smoke tube that circulates the combustion gas that has passed through the furnace tube from the other side in the axial direction toward the one side, and a combustion gas that has passed through the first smoke tube as the shaft. A second smoke pipe that circulates from one side of the direction toward the other side, a first header that guides and circulates the combustion gas that has passed through the furnace tube to the first smoke pipe, and the combustion gas that has passed through the first smoke pipe. A second header that guides and distributes the second smoke pipe,
The furnace tube is connected and supported to the inner wall on one side of the pressure vessel,
The first header is supported from the furnace tube in the vicinity of the other end portion of the furnace tube, and is disposed in a non-contact state with a space in the axial direction from the inner wall on the other axial side of the pressure vessel. And
The second header is supported from the furnace tube in the vicinity of the other end portion of the furnace tube through the first header and the first smoke pipe, and is slidably passed through the furnace tube. and,
In the pressure vessel, the first smoke pipe is disposed above the second smoke pipe,
The superheated steam generator, wherein the second smoke pipe is slidably penetrated with respect to the first header . The furnace tube is configured as a single unit,
The first smoke pipe constituting the superheated steam generator for heating the saturated steam to generate superheated steam is disposed on the surface of the water contained in the pressure vessel,
The overheating according to claim 1, wherein the second smoke pipe constituting the saturated water vapor generating section for heating the water to generate saturated water vapor is disposed below the surface of the water contained in the pressure vessel together with the furnace tube. Steam generator. A partition plate for partitioning the saturated steam generation unit and the superheated steam generation unit is provided inside the pressure vessel, and the flow of the saturated steam flowing through the superheated steam generation unit formed by the partition plate and the first The superheated steam generator according to claim 2 , wherein the flow of the combustion gas flowing through the smoke pipe constitutes a counter flow. The superheated steam generator according to claim 2 or 3 , wherein a baffle plate for guiding a flow of saturated steam is provided in the first smoke pipe in the superheated steam generation unit. Surrounds the first smoke tube constituting the superheated steam generating unit, provided with a closed space forming member for forming a closed space to flow through the saturated steam and superheated steam, the closed space forming member, said pressure vessel The superheated steam generator according to any one of claims 2 to 4 , wherein the superheated steam generator is thermally shielded from an outer surface of the steam generator. The level of the water accommodated in the pressure vessel, in addition to the furnace tube constituting the saturated steam generating portion and the second smoke pipes, also at least a portion of said first smoke tube constituting the superheated steam generating unit When the water stored in the pressure vessel is heated with the combustion gas and saturated water vapor begins to be generated, the water level stored in the pressure vessel is from the water level, lowering the reference level to expose the first smoke tube constituting the reactor tube and the second smoke tube submerged under water and the superheated steam generating unit that constitutes the saturated steam generation unit on the water surface The superheated steam generator according to claim 5 , wherein the superheated steam generator is configured to perform water level control for maintaining the water level of the water stored in the pressure vessel at the reference water level. In the water level control, when the water level stored in the pressure vessel is lowered from the initial water level to the reference water level, the water stored in the pressure vessel is heated with the combustion gas to generate saturated water vapor. And overheating according to claim 6 , wherein the water level is lowered from the initial water level to the reference water level by one or both of the operations of the drainage means for draining the water contained in the pressure vessel. Steam generator. The closed space forming member is smaller than a saturated water vapor inlet for introducing saturated water vapor into the closed space, and allows water to flow between the closed space and the other internal space of the pressure vessel. superheated steam generator as claimed in any one of claims 5-7 hole is formed to be.

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