Superheated water vapor generating device

Abstract

The present invention provides a superheated steam generation device for preventing damage to a steam generation unit in a device for controlling the amount of steam generated in accordance with the amount of power, the superheated steam generation device being provided with: a steam generation unit (2) for generating steam from water by inductively heating a spiral first conductor tube (21); a superheated steam generation unit (3) that inductively heats the spiral second conductor tube (31) and generates superheated steam from the steam; a control unit (61) that controls the amount of water vapor generated by the water vapor generation unit in accordance with the amount of power supplied to the water vapor generation unit; and a safety device (12) that prevents damage to the water vapor generating unit or the superheated water vapor generating unit on the basis of the pressure or temperature of water vapor in the water vapor generating unit, the first conductor tube having a first wound tube portion (21a) wound in a spiral shape, and the second conductor tube having a second wound tube portion (31a) wound in a spiral shape. The safety device is provided to the first winding pipe section or to a communication pipe section that communicates the first winding pipe section and the second winding pipe section.

Description

Technical Field

[0001] This invention relates to a superheated steam generating apparatus. Background Technology

[0002] As a conventional superheated steam generating device, as shown in Patent Document 1, consider the following superheated steam generating device (electrically controlled): a water vapor generating unit of induction heating method that heats water to generate water vapor; and a superheated steam generating unit of induction heating method that heats water vapor to generate superheated steam, wherein the amount of water vapor generated by the water vapor generating unit is controlled according to the electrical power supplied to the water vapor generating unit. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-113282 Summary of the Invention The problem that the invention aims to solve

[0004] In this electrically controlled superheated steam generator, the amount of heat per unit weight of water turning into steam under a specified pressure is fixed as a physical constant. Therefore, by converting the heat of the generated steam into electricity for supply, the amount of steam generated can be highly controllable.

[0005] However, in the electrically controlled method, since the electricity required to generate the desired amount of steam is supplied, a stable amount of steam can be generated. However, the ejection pressure is naturally adjusted according to the amount of steam generated. That is, the ejection pressure increases with the load loss of the steam flow path, and in the worst case, the ejection pressure rises until the device is damaged.

[0006] Therefore, the present invention was made to solve the above-mentioned problems, and its main objective is to prevent damage to the water vapor generating section or the superheated water vapor generating section in a device that controls the amount of water vapor generated according to electrical force. Methods for solving problems

[0007] That is, the superheated steam generating apparatus of the present invention is characterized by comprising: a steam generating section that inductively heats a spiral first conductor tube to generate steam from water; a superheated steam generating section that inductively heats a spiral second conductor tube to generate superheated steam from the steam; a control section that controls the amount of steam generated by the steam generating section based on an electrical force supplied to the steam generating section; and a safety device that prevents damage to the steam generating section or the superheated steam generating section based on the pressure or temperature of the steam in the steam generating section, wherein the first conductor tube has a first wound tube portion wound into a spiral shape, the second conductor tube has a second wound tube portion wound into a spiral shape, and the safety device is provided in the first wound tube portion or in a connecting tube portion between the first wound tube portion and the second wound tube portion.

[0008] In electrically controlled superheated steam generators, for example, when the evaporation temperature increases by 10°C from 120°C to 130°C, the pressure increases by approximately 1.36 times, from approximately 0.199 MPa to approximately 0.27 MPa, but the required enthalpy remains at 1.0055 times, from 2706 kJ / kg to 2721 kJ / kg. While it's difficult to consider a 36% increase in pressure, even then, the steam generation variation is controlled within 0.55%. Furthermore, when the evaporation temperature increases by 55°C from 120°C to 175°C, the pressure increases by approximately 4.49 times, from approximately 0.199 MPa to 0.892 MPa, but the required enthalpy remains at 1.0251 times, from 2706 kJ / kg to 2774 kJ / kg, and the steam generation variation is controlled within 2.51%. The superheated steam generating device of the present invention can activate a safety device when the stability of the steam generation is set within, for example, ±1%, at a pressure of 0.35 MPa (enthalpy of approximately 2730 kJ / kg). At a pressure of 0.35 MPa, compared to 99.63°C (pressure of 0.1 MPa and enthalpy of approximately 2675 kJ / kg), the enthalpy increases by approximately 2.0%, enabling the variation in steam generation to be controlled within ±1%.

[0009] Furthermore, according to the present invention, even if the ejection pressure (and the ejection temperature corresponding to the ejection pressure) increases with the increase of load loss in the steam flow path such as the first conductor tube, damage to the steam generation section or the superheated steam generation section can be prevented by the safety device. In addition, in the present invention, even if the strength of the conductor tube decreases with increasing temperature, damage to the conductor tube can be prevented by the safety device.

[0010] In particular, in this invention, the safety device is located in the first winding section of the first conductor tube or in a connecting pipe section that connects the first winding section of the first conductor tube to the second winding section of the second conductor tube. Therefore, it can directly detect the pressure or temperature rise of the water vapor in the water vapor generating section, preventing damage to the water vapor generating section or the superheated water vapor generating section. Here, the connecting pipe section includes at least a first outlet pipe section and a second inlet pipe section. The first outlet pipe section has a first outlet for discharging water vapor from the first conductor tube, and the second inlet pipe section has a second inlet for introducing water vapor into the second conductor tube.

[0011] As a specific implementation of the safety device, the safety device preferably has a discharge section, which is provided in the first winding tube section or a connecting tube section that connects the first winding tube section and the second winding tube section, to release the water vapor to the outside.

[0012] As another specific embodiment of the safety device, the safety device preferably includes: a pressure sensor disposed in the first winding tube section or a connecting tube section connecting the first winding tube section and the second winding tube section, for detecting the pressure of the water vapor; and a safety circuit for outputting an alarm signal based on the pressure detected by the pressure sensor. Specifically, a safety circuit could compare the boundary point pressure exceeding the target water vapor generation variation with the detection pressure of the pressure sensor, and output an alarm signal if the detection pressure becomes the boundary point pressure. In this structure, the enthalpy value calculated based on the saturated steam temperature is converted into the amount of steam generated, and an alarm is issued when the pressure exceeds the boundary point pressure that represents the target steam generation variation. In electrically controlled superheated steam generators, since pressure reducing valves, steam quantity adjustment valves, and electric proportional valves are not installed, the steam pressure is lower, and the minimum values ​​of 0.1 MPa saturated steam pressure, 99.63°C saturated steam temperature, and 2675 kJ / kg enthalpy can be considered. For example, if the target steam generation variation is ±1.5%, the enthalpy is 2675 × 1.03 = 2755 kJ / kg, corresponding to a saturated steam pressure of 0.6 MPa and a saturated steam temperature of 158.84°C. In this case, the boundary point pressure is set to, for example, 0.6 MPa. That is, if the enthalpy of 2715 kJ / kg used for steam generation is converted into electricity and applied, even if the ejection pressure becomes 0.6 MPa due to increased load pressure loss, the amount of steam generated decreases by approximately 1.47% (2755 / 2715) - 1 ≈ 0.0147. Conversely, when the load pressure loss decreases to 0.1 MPa, it increases by approximately 1.47% (1 - (2675 / 2715) ≈ 0.0147). Therefore, the amount of steam generated varies by approximately ±1.5%. Furthermore, the actual electricity input considers the heat generated to raise the water temperature and the efficiency of heat dissipation devices, but the above calculations only consider the steam generation.

[0013] As another specific embodiment of the safety device, the safety device preferably includes: a temperature sensor disposed in the first winding tube section or a connecting tube section connecting the first winding tube section and the second winding tube section, for detecting the temperature of the water vapor; and a safety circuit for outputting an alarm signal based on the temperature detected by the temperature sensor. Specifically, the preferred safety circuit compares the boundary point temperature that exceeds the variation range of the target water vapor production with the detection temperature of the temperature sensor, and outputs an alarm signal if the detection temperature becomes the boundary point temperature. In this structure, the enthalpy value calculated based on the saturated vapor temperature is converted into the amount of water vapor generated, and an alarm is issued at the boundary point temperature where the variation range of the target water vapor generation exceeds the limit. If the variation range of the target water vapor generation is ±1.5% as described above, the boundary point temperature can be set, for example, to 158.84°C.

[0014] As another specific embodiment of the safety device, the safety device preferably includes: a pressure sensor disposed in the first winding tube section or a connecting tube section connecting the first winding tube section and the second winding tube section, for detecting the pressure of the water vapor; a temperature sensor disposed in the first winding tube section or a connecting tube section connecting the first winding tube section and the second winding tube section, for detecting the temperature of the water vapor; and a safety circuit that outputs an alarm signal based on the pressure detected by the pressure sensor and the temperature detected by the temperature sensor.

[0015] Preferably, the safety circuit outputs an attention signal in the stage before outputting the alarm signal. If this structure is used, an attention signal is output before an alarm signal is output, thus prompting an inspection of the user-side equipment of the superheated steam generator 100.

[0016] It is possible that the safety device is also provided in the second winding tube section or the second outlet tube section having a second outlet for discharging superheated steam, to prevent damage to the steam generating section or the superheated steam generating section based on the pressure or temperature of the superheated steam. If this structure is used, the pressure or temperature rise in the steam generation section can be indirectly detected by the pressure or temperature of the superheated steam in the superheated steam generation section, thus preventing damage to the steam generation section or the superheated steam generation section. Invention Effects

[0017] According to the present invention configured in this way, in a device that controls the amount of water vapor generated based on electrical force, damage to the water vapor generating section or the superheated water vapor generating section can be prevented. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing the structure of the superheated steam generating apparatus of the first embodiment. Figure 2 This is a diagram showing an example of a hollow conductor tube with the same implementation. Figure 3 This diagram mainly shows the core structure of each steam generation section in the same embodiment. Figure 4 This is a diagram showing a modified example of the core structure of each steam generation section in the same embodiment. Figure 5 This is a diagram showing the wiring of the induction coils in each steam generation unit of the same embodiment. Figure 6 This is a diagram schematically illustrating the structure of a control device with the same implementation. Figure 7 This is a schematic diagram showing the structure of the superheated steam generating device according to the second embodiment. Figure 8 It is a graph showing the operation of a superheated steam generating device with the same implementation. Figure 9 This is a diagram schematically illustrating the structure of a superheated steam generating device according to a modified embodiment. Figure 10 This is a diagram schematically illustrating the structure of a superheated steam generating device according to a modified embodiment. Detailed Implementation

[0019] <First Implementation> Hereinafter, a first embodiment of the superheated steam generating apparatus of the present invention will be described with reference to the accompanying drawings.

[0020] The superheated steam generating apparatus 100 of this embodiment heats water to generate superheated steam exceeding 100°C (200°C to 2000°C).

[0021] Specifically, such as Figure 1 As shown, the superheated steam generating apparatus 100 includes: a steam generating unit 2 (hereinafter referred to as a saturated steam generating unit 2) that heats water to generate saturated steam; and a superheated steam generating unit 3 that heats the saturated steam to generate superheated steam. Additionally, in Figure 1 The diagram of the power supply circuit is omitted.

[0022] <Structure of Saturated Water Vapor Generating Unit 2> The saturated water vapor generating unit 2 is an induction heating unit and includes: a first conductor tube 21 wound into a spiral shape; and a magnetic flux generating mechanism 22 for induction heating the first conductor tube 21.

[0023] like Figure 2 As shown, the first conductor tube 21 is formed from a metal tube and has a spirally wound portion, namely the first wound tube portion 21a. A first inlet P1 for introducing water is formed at one end, and a first outlet P2 for discharging the generated saturated water vapor is formed at the other end. The first inlet P1 is formed in the first inlet tube portion 21b, which extends outward from one end of the first wound tube portion 21a. Similarly, the first outlet P2 is formed in the first outlet tube portion 21c, which extends outward from the other end of the first wound tube portion 21a. This first conductor tube 21 serves as a container for generating saturated water vapor. Furthermore, the first conductor tube 21 can be made of austenitic stainless steel such as SUS304, or alloys such as chromium-nickel-iron alloys, which have high heat resistance and mechanical strength. Moreover, the adjacent wound portions of the first conductor tube 21 are electrically connected by welding or the like.

[0024] The flux generating mechanism 22 includes an iron core 22a and an induction coil 22b wound along the iron core 22a. An AC power source is connected to the induction coil 22b, supplying it with controlled power. The AC power source has a commercial frequency of 50Hz or 60Hz. The induction coil 22b, powered by this AC power source, is the primary coil. As a result of being powered by this primary coil, an induced current flows in a first conductor tube 21, which is a secondary coil wound once. Furthermore, the first conductor tube 21 generates Joule heating, heating the water inside the first conductor tube 21 to generate saturated water vapor. Additionally, water is stored in the first conductor tube 21 to a predetermined height.

[0025] <Structure of Superheated Steam Generation Unit 3> The superheated steam generating unit 3 is an induction heating unit, which includes a second conductor tube 31 wound into a spiral shape and a magnetic flux generating mechanism 32 for induction heating the second conductor tube 31.

[0026] like Figure 2 As shown, the second conductor tube 31 is formed from a metal tube and has a spirally wound portion, namely the second wound tube portion 31a. A second inlet port P3 is formed at one end, allowing steam to enter the saturated steam generation section 2, and a second outlet port P4 is formed at the other end, allowing the generated superheated steam to exit. The second inlet port P3 is formed in the second inlet tube portion 31b, which extends outward from one end of the second wound tube portion 31a. Similarly, the second outlet port P4 is formed in the second outlet tube portion 31c, which extends outward from the other end of the second wound tube portion 31a. This second conductor tube 31 serves as a container for generating superheated steam. Furthermore, the second conductor tube 31 can be made of austenitic stainless steel such as SUS304, or alloys such as chromium-nickel-iron alloys, which have high heat resistance and mechanical strength. Moreover, the adjacent wound portions of the second conductor tube 31 are electrically connected by welding or the like.

[0027] At the second inlet P3, an external pipe or the first outlet P2 of the first conductor pipe 21 of the saturated steam generating unit 2 is connected. This external pipe supplies steam from the saturated steam generating unit 2 to the second conductor pipe 31. Specifically, the first wound section 21a of the first conductor pipe 21 and the second wound section 31a of the second conductor pipe 31 are connected by a connecting pipe section CP, which includes at least a first outlet pipe section 21c and a second inlet pipe section 31b. Furthermore, if an external pipe is present, it also becomes part of the connecting pipe section CP. Additionally, at the second outlet P4, an external pipe is connected for supplying the generated superheated steam to the utilization side (e.g., a heat treatment chamber).

[0028] The flux generating mechanism 32 includes an iron core 32a and an induction coil 32b wound along the iron core 32a. An AC power source is connected to the induction coil 32b, supplying it with controlled power. The AC power source has a commercial frequency of 50Hz or 60Hz. The induction coil 32b, powered by this AC power source, is the primary coil. As a result of being powered by this primary coil, an induced current flows through the second conductor tube 31, which is a secondary coil wound once. Furthermore, the second conductor tube 31 generates Joule heating, heating the water vapor flowing inside.

[0029] like Figure 3 and Figure 4 As shown, in the superheated steam generating apparatus 100 of this embodiment, in addition to the iron core 22a of the saturated steam generating section 2 and the iron core 32a of the superheated steam generating section 3, a common iron core 41 is also provided, which serves as a common path for the magnetic flux generated by the two iron cores 22a and 32a. Furthermore, by connecting the iron cores 42 and 43, the common iron core 41 and the upper and lower parts of the two iron cores 22a and 32a are respectively connected to form a single three-legged iron core. With this structure, the overall size of the iron core can be reduced, thereby achieving a compact overall apparatus. That is, the superheated steam generating apparatus 100 of this embodiment uses a single three-legged iron core to construct the saturated steam generating section 2 and the superheated steam generating section 3.

[0030] In addition, Figure 3 and Figure 4 In the diagram, from a top-down view, the individual iron cores 22a, 32a, and 41 are arranged at the vertices of a triangle, and the connecting iron cores 42 and 43 are bent with the shared iron core 41 as the bending point. This reduces the distance between the two iron cores 22a and 32a, decreases the overall width dimension of the tripod iron core, and achieves space saving.

[0031] Furthermore, in this embodiment, the induction coil 22b of the saturated steam generator 2 and the induction coil 32b of the superheated steam generator 3 are connected in a Scott connection manner to convert the three-phase AC power from the three-phase AC power supply 5 into two single-phase AC power (see reference). Figure 5 That is, the superheated steam generating device 100 of this embodiment is configured to have a Scott-connected transformer with a single three-legged iron core. When the Scott-connected transformer is composed of a main transformer and a T-type transformer, the part corresponding to the saturated steam generating unit 2 becomes the main transformer, and the part corresponding to the superheated steam generating unit 3 becomes the T-type transformer.

[0032] In addition, such as Figure 5 As shown, a first control device 10 for controlling voltage or current is installed on one of the two phases of the input side of the main transformer. Additionally, in Figure 5In this system, a semiconductor control element such as a thyristor is installed as the first control device 10 on the V phase of the input side of the main transformer. Furthermore, a second control device 11 for controlling voltage or current is installed on one end of the primary coil (induction coil 32b) of the T-type transformer (the U-phase side or the midpoint O side of the T-type primary coil). This second control device 11 is also the same as the first control device 10, using a semiconductor control element such as a thyristor. The control device 6 is configured to individually control the voltage applied to the primary coil (induction coil 22b) of the main transformer and the voltage applied to the primary coil (induction coil 32b) of the T-type transformer by controlling the first control device 10 and the second control device 11. Additionally, the control device 6 is a computer having a CPU, memory, input / output interfaces, etc.

[0033] Control of Superheated Steam Generator 100 The control device 6 controls the amount of saturated water vapor in the saturated water vapor generating unit 2 as follows.

[0034] like Figure 6 As shown, the control device 6 includes a steam quantity control unit 61, which controls the amount of saturated steam generated by the saturated steam generating unit 2 based on the electrical force supplied to the saturated steam generating unit 2. Furthermore, the control device 6 also includes a relational data storage unit 62, which stores relational data representing the relationship between the amount of steam generated by the saturated steam generating unit 2 and the electrical force supplied to the saturated steam generating unit 2.

[0035] The relational data stored in the relational data storage unit 62 is obtained by actually measuring the amount of water vapor generated by the saturated water vapor generating unit 2 and the electrical force supplied to the saturated water vapor generating unit 2. In addition, the relational data is actually measured under atmospheric pressure conditions when the first outlet P2 of the first conductor tube 21 of the saturated water vapor generating unit 2 is open.

[0036] Furthermore, the steam quantity control unit 61 obtains electrical power data from the power meter 7, which measures the amount of electricity supplied to the saturated steam generation unit 2, and uses this data to control the first control device 10 to achieve a predetermined steam quantity. Specifically, the steam quantity control unit 61 controls the first control device 10 so that the electrical power obtained from the power meter 7 becomes the target electrical power calculated based on the relationship data and the predetermined steam quantity. Additionally, the power meter 7 is installed on any one of the two phases of the input side of the main transformer constituting the saturated steam generation unit 2. That is, in this embodiment, the saturated steam quantity is controlled solely based on the electrical power obtained from the power meter 7.

[0037] In the superheated steam generating device 100 that controls the amount of steam, the saturated steam generating unit 2 and the superheated steam generating unit 3 operate under atmospheric pressure. Furthermore, specifically in the connecting pipe CP between the saturated steam generating unit 2 and the superheated steam generating unit 3, no pressure reducing valve, steam quantity adjusting valve, or electric proportional valve is installed.

[0038] Furthermore, during the period from startup to the aforementioned steam quantity control, the control device 6 controls the first control device 10 to supply the power to the saturated steam generating unit 2 at a value below the maximum value or the value at which no malfunction occurs in any part. Then, this control is performed until the water in the saturated steam generating unit 2 is about to reach 100°C, for example, 95°C, after which the process switches to the aforementioned steam quantity control.

[0039] In addition, the control device 6 controls the temperature of the superheated steam generated by the superheated steam generating unit 3 as follows.

[0040] In the superheated steam generating apparatus 100 of this embodiment, the temperature of the superheated steam discharged from the second conductor pipe 31 of the superheated steam generating unit 3 or the piping temperature of the second outlet P4 of the second conductor pipe 31 is detected by the temperature detector 8.

[0041] Furthermore, the control device 6 also includes a temperature control unit 63, which inputs a control signal corresponding to the deviation between the detected temperature obtained by the temperature detector 8 and the target temperature of the superheated steam into the second control device 11 to control the AC voltage applied to the induction coil 32b. The temperature control unit 63 performs feedback control on the temperature of the superheated steam heated by the second conductor tube 31 so that its deviation from the target temperature is less than ±1°C.

[0042] Furthermore, in this embodiment, a safety device 12 is also provided, which prevents the saturated steam generating unit 2 from breaking based on the pressure or temperature of the steam generated by the steam generating unit 2.

[0043] Figure 1 The safety device 12 shown is provided between the saturated steam generating unit 2 or the steam generating unit 2 and the superheated steam generating unit 3, and has a discharge unit 12a that releases the steam generated by the saturated steam generating unit 2 to the outside.

[0044] The discharge section 12a is a safety valve that releases steam to the outside when a set pressure is reached. Specifically, the safety valve 12a releases steam from inside the first conductor tube 21 to the outside when the steam pressure is less than 1 MPa (equivalent to 179.88°C). The superheated steam generating device 100 of this embodiment is equivalent to a small once-through boiler or a simple once-through boiler according to the boiler and pressure vessel safety regulations. For example, the safety valve 12a releases steam from inside the first conductor tube 21 to the outside when the steam pressure is 0.4 MPa (specifically 0.4758 MPa (equivalent to 150°C)). Furthermore, the safety valve 12a is provided in the first wound section 21a or the connecting section CP of the first conductor tube 21, which connects the first wound section 21a of the first conductor tube 21 to the second wound section 31a of the second conductor tube 31. In this embodiment, the safety valve 12a is provided in the first outlet pipe section 21c within the connecting pipe section CP. Alternatively, the safety valve 12a may be provided at the upper part of the first winding pipe section 21a. Furthermore, the safety valve 12a may also be provided in the second inlet pipe section 31b of the second conductor pipe 31.

[0045] The superheated steam generating device 100 configured in this way can stably generate a certain amount of steam by supplying the electricity required for the desired amount of steam. As a result, the output of superheated steam at a specified temperature can be stabilized within an error range of ±1%. Furthermore, even if the ejection pressure increases with the increase of load loss in the steam flow path, when the specified pressure is reached, the safety valve 12a releases the steam inside the first conductor pipe 21 to the outside, thus preventing damage to the superheated steam generating device, including the steam generating unit 2.

[0046] Steam heating is a method that allows for relatively uniform heating even of loads with complex shapes by bypassing them with steam. Furthermore, due to the extremely low oxygen content, it is safe in terms of explosion-proof and flammability. Since the energy supplied by steam is essentially proportional to the product of steam temperature and steam quantity, conventional boilers control the steam quantity by controlling steam pressure using pressure-reducing valves and adjusting the steam flow path area using proportional valves. However, valve control based on such mechanical structures struggles to achieve precise control and reproducibility, thus limiting the application of steam heating to precision machining. This embodiment, with its electrically controlled system, overcomes these difficulties, realizing steam heating as a uniform and highly precise heating method.

[0047] <Second Implementation Method> Next, refer to Figure 7The superheated steam generating apparatus 100 of the second embodiment will be described. Compared with the first embodiment, the superheated steam generating apparatus 100 of the second embodiment has the same structure for the saturated steam generating section 2 and the superheated steam generating section 3, but the structure for the safety device 12 is different.

[0048] Specifically, such as Figure 7 As shown, the safety device 12 includes: a pressure sensor 12b, which detects the pressure of the water vapor generated by the saturated water vapor generating unit 2; a temperature sensor 12c, which detects the temperature of the water vapor generated by the saturated water vapor generating unit 2; and a safety circuit 12d, which outputs an alarm signal to cut off or limit the power supply to the saturated water vapor generating unit 2 based on the pressure detected by the pressure sensor 12b and the temperature detected by the temperature sensor 12c. The pressure sensor 12b and the temperature sensor 12c are disposed between the water vapor generating unit 2 or between the water vapor generating unit 2 and the superheated water vapor generating unit 3. Specifically, the pressure sensor 12b and the temperature sensor 12c are disposed in the first winding tube section 21a or the connecting tube section CP of the first conductor tube 21, which connects the first winding tube section 21a of the first conductor tube 21 to the second winding tube section 31a of the second conductor tube 31. Furthermore, the water vapor quantity control unit 61 cuts off or limits the power supply to the saturated water vapor generating unit 2 based on the alarm signal output from the safety circuit 12d. In addition, the safety circuit 12d can also send an alarm signal to the user based on the pressure detected by the pressure sensor 12b and the temperature detected by the temperature sensor 12c.

[0049] Here, the safety circuit 12d compares the detected pressure of the pressure sensor 12b with a threshold pressure less than 1 MPa (e.g., 0.35 MPa), and outputs an alarm signal if the detected pressure is above the threshold pressure. Furthermore, the safety circuit 12d compares the detected temperature of the temperature sensor 12c with a threshold temperature less than 179.88°C, and outputs an alarm signal if the detected temperature is above the threshold temperature.

[0050] In this way, the safety circuit 12d sets a threshold temperature (alarm temperature) or a threshold pressure (alarm pressure) based on the variation in the target water vapor generation (e.g., ±1%). This allows for countermeasures to be taken at the user's side to reduce the pressure loss in the water vapor flow path. In the power control method, the stability of the generated water vapor quantity can be numerically determined, improving user convenience.

[0051] Specifically, the safety circuit 12d can compare the boundary point pressure exceeding the target steam generation variation with the detection pressure of the pressure sensor 12b, and output an alarm signal if the detected pressure is the boundary point pressure. Furthermore, the steam quantity control unit 61 can cut off or limit the power supply to the saturated steam generation unit 2 when an alarm signal is output from the safety circuit 12d. In the electrically controlled superheated steam generation device, since no pressure reducing valve, steam quantity adjustment valve, or electric proportional valve is installed, the steam pressure is lower, and the minimum values ​​of saturated steam pressure 0.1 MPa, saturated steam temperature 99.63°C, and enthalpy 2675 kJ / kg can be considered. For example, if the target steam generation variation is ±1.5%, the enthalpy is 2675 × 1.03 = 2755 kJ / kg, and the corresponding saturated steam pressure is 0.6 MPa, and the saturated steam temperature is 158.84°C. In this case, the boundary point pressure is set to, for example, 0.6 MPa. In addition, the boundary point pressure can be set to a pressure lower than the set pressure of the discharge section 12a.

[0052] Furthermore, the safety circuit 12d can also output a warning signal if the detection pressure of the pressure sensor 12b exceeds the boundary point pressure (e.g., 0.6 MPa) or is lower than the threshold pressure (alarm pressure, e.g., 0.35 MPa) by a predetermined threshold pressure (caution pressure, e.g., 0.30 MPa). Here, the caution pressure is set to a pressure at which the user-side equipment of the assembled superheated steam generator 100 will not be damaged. By outputting a warning signal based on the caution pressure in this way, it is possible to prompt the inspection of the user-side equipment of the assembled superheated steam generator 100.

[0053] Furthermore, the safety circuit 12d can compare the boundary temperature exceeding the target water vapor generation variation range with the temperature detected by the temperature sensor 12c, and output an alarm signal if the detected temperature is the boundary temperature. Additionally, the water vapor quantity control unit 61 can cut off or limit the power supply to the saturated water vapor generation unit 2 if an alarm signal is output from the safety circuit 12d. If the target water vapor generation variation range is ±1.5% as described above, the boundary temperature can be set, for example, to 158.84°C. Furthermore, the boundary temperature is set to a temperature at which the corresponding saturated vapor pressure is less than the set pressure of the discharge unit 12a.

[0054] Furthermore, the safety circuit 12d can also output a warning signal if the temperature detected by the temperature sensor 12c exceeds the boundary point temperature (e.g., 158.84°C) or is lower than the threshold temperature (alarm temperature) by a predetermined threshold temperature (caution temperature). Here, the caution temperature is set to a temperature at which the user-side equipment of the superheated steam generator 100 will not be damaged. By outputting a warning signal based on the caution temperature in this way, the inspection of the user-side equipment of the superheated steam generator 100 can be prompted.

[0055] The heat required for the steam generation unit 2, as well as the heat needed to raise the water temperature to 99.63°C, is inherent to each model and will not vary significantly if the inlet water temperature range is specified. Furthermore, heat dissipation from piping, etc., is also temperature-dependent, but the generated steam temperature is a relatively low value of 100-180°C, and due to insulation, it is small compared to the latent heat of vaporization, thus having a minor impact. By taking this heat dissipation into account in the calculation of the actual measured variations, accurate boundary point pressure or boundary point temperature can be calculated.

[0056] In addition, safety device 12 can also be in Figure 7 It has the structure of the discharge section 12a of the first embodiment described above, based on the existing structure.

[0057] Safety device 12 has a structure that includes a discharge section 12a based on safety circuit 12d, thereby enabling... Figure 8 As shown, the superheated steam generating device 100 performs the following phased operations: as the first phase, it outputs a warning signal (preparatory alarm) based on the warning pressure (warning temperature); as the second phase, it cuts off or restricts the power supply to the saturated steam generating unit 2 based on the alarm pressure (alarm temperature); and as the third phase, it releases steam to the outside through the release unit 12a.

[0058] Furthermore, safety device 12 can also be in Figure 7 The structure does not include a temperature sensor 12c. In this case, the safety circuit 12d outputs an alarm signal based on the detected pressure of the pressure sensor 12b. The alarm signal is used to cut off or limit the power supply to the saturated water vapor generating unit 2.

[0059] Furthermore, safety device 12 can also be used in Figure 7 The structure does not have a pressure sensor 12b. In this case, the safety circuit 12d outputs an alarm signal based on the temperature detected by the temperature sensor 12c. The alarm signal is used to cut off or limit the power supply to the saturated water vapor generating unit 2.

[0060] <Other variations and implementations> In addition to a safety valve that opens when a set pressure is reached, the discharge section 12a of the safety device 12 can also be a device that releases water vapor to the outside based on an opening signal from the outside. In this configuration, as... Figure 9 As shown, the safety circuit 12d can output an open signal to the discharge unit 12a based on the pressure detected by the pressure sensor 12b or the temperature detected by the temperature sensor 12c.

[0061] Furthermore, such as Figure 10 As shown, the safety device 12 can be installed in the second winding tube section 31a or the second outlet tube section 31c of the superheated steam generating section 3, or it can be installed in the steam generating section 2 or the water supply pipe 13 that supplies water to the steam generating section 2. Alternatively, these structures can be incorporated into a structure in which the safety device 12 is installed in the first winding tube section 21a or the connecting pipe section CP.

[0062] When the safety device 12 is installed in the superheated steam generating section 3, such as Figure 10 As shown, the discharge section 12a or pressure sensor 12b can be installed via measuring pipe 14 at or near the second outlet P4 of the second outlet section 31c of the second conductor pipe 31 (e.g., the straight pipe section). Alternatively, the temperature sensor 12c can be installed at or near the second outlet P4 of the second outlet section 31c of the second conductor pipe 31 (e.g., the straight pipe section). The safety operation of each component using discharge section 12a, pressure sensor 12b, or temperature sensor 12c is as described above. Regarding the safety operation using temperature sensor 12c, since the superheated steam generation section 3 is temperature-controlled, its function depends on its set temperature. For example, when the set temperature of the superheated steam is 150°C, the temperature rises with increasing load loss in the steam flow path, resulting in the control input of temperature control section 63 sometimes becoming zero. Subsequently, as the temperature of the superheated steam gradually rises, the safety operation using temperature sensor 12c functions.

[0063] Furthermore, when the safety device 12 is installed in the first inlet pipe 21b of the steam generating unit 2 or the water supply pipe 13, such as Figure 10 As shown, the aforementioned discharge section 12a or pressure sensor 12b can be installed at or near the first inlet P1 of the first inlet pipe section 21b of the steam generation section 2 (e.g., the straight pipe section) or the water supply pipe 13. Furthermore, the safety operation of each part using the discharge section 12a or pressure sensor 12b is as described above.

[0064] Furthermore, the location of the discharge section 12a in the safety device 12 can be different from the location of the pressure sensor 12b or the temperature sensor 12c. For example, the pressure sensor 12b or the temperature sensor 12c can be configured to be located between the steam generating section 2 or between the steam generating section 2 and the superheated steam generating section 3, and the discharge section 12a can be located in the steam generating section 2 or the water supply pipe 13 to discharge water. Alternatively, the pressure sensor 12b or the temperature sensor 12c can be located in the superheated steam generating section 3, and the discharge section 12a can be located in the steam generating section 2 or the water supply pipe 13 to discharge water. Furthermore, the pressure sensor 12b can be located in the water supply pipe 13, and the discharge section 12a can be located in the steam generating section 2 or between the steam generating section 2 and the superheated steam generating section 3 to discharge steam.

[0065] Alternatively, a third inlet can be provided in the connecting pipe section CP of the above embodiment to introduce steam, superheated steam, or other gases other than steam from the outside, or a third inlet pipe section may have such a third inlet. For example, steam generated by an external boiler, superheated steam introduced into the heat treatment chamber and then recirculated, or nitrogen gas may be introduced into the third inlet. In this case, a safety device 12 is provided in the connecting pipe section CP by providing a safety device 12 in the third inlet pipe section.

[0066] In addition to induction heating, the saturated steam generating section 2 and the superheated steam generating section 3 can also be electrically heated. In this case, an AC or DC power supply is connected to both ends of the conductor tubes 21 and 31 through which the fluid flows, and the conductor tubes 21 and 31 are heated by Joule heating by flowing AC or DC current in them. In this case, the conductor tubes 21 and 31 can be formed into various shapes, such as having multiple straight sections and multiple curved sections connecting two straight sections, in addition to being spiral.

[0067] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from its spirit. Explanation of reference numerals in the attached figures:

[0068] 100: Superheated steam generator; 2: Saturated steam generator (steam generator); 3: Superheated steam generator; 61: Steam quantity control unit (control unit); 12: Safety device; 12a: Discharge unit; 12b: Pressure sensor; 12c: Temperature sensor; 12d: Safety circuit.

Claims

1. A superheated steam generating device, wherein, have: The steam generation section uses induction heating of the spiral-shaped first conductor tube to generate steam from water. The superheated steam generation unit induction heats the spiral-shaped second conductor tube to generate superheated steam from the water vapor; The control unit controls the amount of water vapor generated by the water vapor generating unit based on the electrical power supplied to the water vapor generating unit; as well as Safety devices prevent damage to the steam generating unit or the superheated steam generating unit based on the pressure or temperature of the steam in the steam generating unit. The first conductor tube has a first wound tube portion wound into a spiral shape. The second conductor tube has a second wound tube portion wound into a spiral shape. The safety device is disposed in the first winding tube section or in a connecting tube section that connects the first winding tube section and the second winding tube section.

2. The superheated steam generating device according to claim 1, wherein, The first conductor tube has a first outlet section, and the first outlet section has a first outlet for discharging water vapor. The second conductor tube has a second inlet section, which has a second inlet for introducing water vapor. The connecting tube section includes at least the first outlet tube section and the second inlet tube section.

3. The superheated steam generating device according to claim 1 or 2, wherein, The safety device has a discharge section, which is disposed in the first winding tube section or a connecting tube section connecting the first winding tube section and the second winding tube section, and discharges the water vapor to the outside.

4. The superheated steam generating device according to claim 1, wherein, The safety device has the following features: A pressure sensor is disposed in the first winding tube section or in a connecting tube section that connects the first winding tube section and the second winding tube section to detect the pressure of the water vapor; as well as The safety circuit outputs an alarm signal based on the pressure detected by the pressure sensor.

5. The superheated steam generating device according to claim 1, wherein, The safety device has the following features: A temperature sensor is disposed in the first winding tube section or in a connecting tube section that connects the first winding tube section and the second winding tube section to detect the temperature of the water vapor; as well as The safety circuit outputs an alarm signal based on the temperature detected by the temperature sensor.

6. The superheated steam generating device according to claim 1, wherein, The safety device has the following features: A pressure sensor is disposed in the first winding tube section or in a connecting tube section that connects the first winding tube section and the second winding tube section to detect the pressure of the water vapor; A temperature sensor is disposed in the first winding tube section or in a connecting tube section that connects the first winding tube section and the second winding tube section to detect the temperature of the water vapor; as well as The safety circuit outputs an alarm signal based on the pressure detected by the pressure sensor and the temperature detected by the temperature sensor.

7. The superheated steam generating apparatus according to any one of claims 4 to 6, wherein, The safety circuit outputs an attention signal in the stage before outputting the alarm signal.

8. The superheated steam generating device according to claim 1, wherein, The safety device is also provided on the second winding tube section or the second outlet tube section having a second outlet for discharging superheated steam, to prevent damage to the steam generating section or the superheated steam generating section based on the pressure or temperature of the superheated steam.

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