JP6985734B2 - Superheated steam generator and its maintenance method - Google Patents

Description

The present invention relates to a superheated steam generator and a maintenance method thereof.

An austenitic stainless steel such as SUS304 or an alloy such as Inconel, which has high heat resistance and mechanical strength, is used for the superheated steam generating portion of the induction heating method or the energization heating method (for example, Patent Document 1).

However, although the melting point of these stainless steels and alloys is about 1400 ° C., the volume decreases due to steam oxidation under high temperature superheated steam exceeding 1000 ° C.

Since the above-mentioned superheated steam generating part has a conductor tube made of stainless steel or an alloy, if the volume of the conductor tube decreases due to steam oxidation, it cannot withstand the pressure and thermal expansion deformation of the superheated steam, and the conductor. The tube will be damaged. If superheated steam leaks to the outside due to damage to the conductor tube, it may cause a fire or damage to the human body.

Japanese Unexamined Patent Publication No. 2016-176613

Therefore, the present invention has been made to solve the above-mentioned problems, and its main task is to inform the user of the maintenance time of the superheated steam generator.

That is, the superheated steam generator according to the present invention has a superheated steam generating unit of an induction heating method or an energization heating method that heats steam to generate superheated steam, an operating temperature of the superheated steam generating unit, and an operating time at the operating temperature. It is characterized in that it is provided with a notification unit that emits maintenance information with the above as a parameter.

In such a case, since maintenance information is issued with the operation time at the operating temperature as a parameter, the maintenance time of the superheated steam generator can be notified to the user, and the user can notify the user before the superheated steam generator fails. Maintenance can be performed.

The degree of deterioration and wear of the superheated steam generator varies depending on the operating temperature. Therefore, the notification unit acquires operating temperature data indicating the operating temperature of the superheated steam generating unit and operating time data indicating the operating time at the operating temperature, and converts the operating time into a predetermined temperature (for example, 1200 ° C.). It is desirable to integrate and issue the maintenance information when the integrated value exceeds a predetermined integration threshold.

Some superheated steam generators have a conductor tube that is induced to be heated or energized to generate superheated steam, and a steam amount adjusting mechanism for adjusting the amount of superheated steam to be generated. The flow velocity of superheated steam in the conductor tube increases or decreases depending on the increase or decrease in the amount of superheated steam produced. If the flow velocity is large, the volume reduction rate is large, and if the flow velocity is small, the volume reduction rate is small.
In the actual measurement at 1200 ° C, the volume reduction rate is proportional to the 0.8th power of the flow velocity, so if the amount of superheated steam generated is half, the flow velocity will also be halved, and the corrected integrated value (operating time) will be the integrated value before correction. The value is 0.5 ^0.8 = 0.574 times the value. That is, in the case of producing superheated steam at the same temperature, assuming that the operation is performed at 100% production amount for 1000 hours, the operation time is 574 hours when operating at 50% production amount.
Since the volume reduction rate differs depending on the amount of superheated steam generated in this way, the notification unit corrects the integrated value based on the amount of superheated steam generated by the superheated steam generation unit, and the corrected integrated value is the integrated value. It is desirable to issue the maintenance information when the threshold value is exceeded.

The heated steam generating unit has a conductor tube that generates superheated steam by induction heating or energization heating. This conductor tube is easily oxidized by steam due to superheated steam, and the volume reduction becomes remarkable. Therefore, it is desirable that the notification unit emits maintenance information including the replacement time of the conductor tube.

It is unlikely that the life of the equipment will become a problem even if the operating time at a temperature at which the volume reduction due to steam oxidation is not substantially a problem is not taken into consideration. For example, when superheated steam at 1000 ° C. is passed through a conductor tube made of Inconel for 1000 hours, the volume reduction rate is about 5%. That is, at 1000 ° C. or lower, it takes tens of thousands of hours for the remaining amount of the distribution pipe to reach 10% or less, so it is unlikely that the device life will become a problem in a short time. Therefore, it is desirable that the notification unit emits the maintenance information with the operating temperature at which the volume reduction rate of the distribution pipe becomes a predetermined value or more when operated for a predetermined time as a parameter. Further, the notification unit defines a temperature range used for maintenance information in the operating temperature of the superheated steam generating unit, and sets the operating time at the operating temperature included in the temperature range as the operating time at the maximum temperature in the temperature range. It is desirable to handle it.

As a specific configuration of the superheated steam generation unit, a first superheated steam generation unit of an induction heating method in which a conductor tube through which steam flows is induced and heated as a secondary coil, and a superheated steam generated by the first superheated steam generation unit. It is conceivable that the conductor tube through which the steam flows is energized and heated to further heat the superheated steam, and the second superheated steam generating unit of the energization heating method is provided.
In this configuration, a method of using the second superheated steam generating section at a higher temperature than the first superheated steam generating section to accelerate the consumption of the conductor tube of the second superheated steam generating section can be considered. In this case, it is desirable that the notification unit is provided on the side of the second superheated steam generation unit and emits maintenance information indicating the replacement time of the conductor tube of the second superheated steam generation unit.

Further, it is desirable that the notification unit is also provided on the side of the first superheated steam generating unit to generate maintenance information indicating the replacement time of the conductor tube of the first superheated steam generating unit. This makes it possible to inform the user of the maintenance time of the first superheated steam generating unit in addition to the second superheated steam generating unit. However, the frequency of performing maintenance such as replacement of the conductor pipe of the second superheated steam generating unit is higher than the frequency of performing maintenance such as replacement of the conductor pipe of the first superheated steam generating unit.

In the first superheated steam generator of the induction heating method, since the conductor tube is wound around the iron core, it is difficult and time-consuming to disassemble to replace the conductor tube, and maintenance such as replacement of the conductor tube is required. Although it is difficult to do, the second superheated steam generator of the energization heating method can be easily replaced and maintained by a simple operation such as removing the power supply wiring from the power supply terminal of the conductor tube. Therefore, the first superheated steam generator is used under usage conditions (for example, less than 1000 ° C.) where the conductor tube is less deteriorated and consumed, and the frequency of maintenance such as replacement is minimized. On the other hand, since the second superheated steam generation unit is easy to replace and maintain the conductor tube, superheated steam at a high temperature (for example, 1000 ° C. or higher) is generated here.

According to the present invention configured as described above, since maintenance information is issued with the operation time at the operating temperature as a parameter, the user can be informed of the maintenance time of the superheated steam generator, and the user can fail the superheated steam generator. Maintenance can be done before doing so.

It is a figure which shows typically the structure of the superheated steam generator which concerns on this embodiment. It is a perspective view which shows an example of the conductor tube of the superheated steam generation part which concerns on the same embodiment. It is a figure which shows the superheated steam-Inconel 601 alloy volume reduction rate characteristic after 1000 hours. It is a figure which shows typically the structure of the superheated steam generator which concerns on a modification embodiment.

Hereinafter, an embodiment of the superheated steam generator according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, the superheated steam generator 100 according to the present embodiment has a superheated steam generator 10 that heats water or steam to generate superheated steam of more than 100 ° C. (200 ° C. to 2000 ° C.).

The superheated steam generation unit 10 is of an induction heating method, and has a spirally wound circular tubular conductor tube 2 and a magnetic flux generation mechanism 3 for inductively heating the conductor tube 2. There is.

As shown in FIG. 2, the conductor tube 2 is formed of one metal tube and has a spirally wound winding portion, and water or steam is contained at one end thereof. An introduction port P1 to be introduced is formed, and a derivation port P2 for deriving the generated superheated steam is formed at the other end. For the conductor tube 2, an alloy such as austenitic stainless steel such as SUS304 or Inconel, which has high heat resistance and mechanical strength, can be used.

An external pipe for supplying water or steam to the conductor pipe 2 is connected to the introduction port P1. In this embodiment, an induction heating type saturated steam generation unit (not shown) is connected. The configuration of the saturated steam generating unit is the same as the configuration of the superheated steam generating unit 10. Further, an external pipe for supplying the generated superheated steam to the user side (for example, a heat treatment chamber) is connected to the lead-out port P2.

The magnetic flux generation mechanism 3 includes an iron core 31 and an induction coil 32 wound along the iron core 31. An AC power supply 4 is connected to the induction coil 32, and controlled power is supplied to the induction coil 32. The power supply frequency of the AC power supply 4 is a commercial frequency of 50 Hz or 60 Hz. The induction coil 31 to which power is supplied by the AC power supply 4 becomes a primary coil, and as a result of being fed by the primary coil, an induced current flows through the conductor tube 2 and the conductor tube 2 becomes a secondary coil. Then, the conductor tube 2 generates Joule heat, and the water vapor flowing inside is heated.

In the superheated steam generator 100, the temperature of the superheated steam derived from the conductor tube 2 is detected by the temperature detector 5, and a control signal corresponding to the deviation between the detected temperature and the target temperature is sent to the voltage controller 6 (for example,). The AC voltage applied to the induction coil 32 by inputting to the thyristor) is controlled. Specifically, the temperature control unit 7 that performs this control feedback-controls the temperature of the superheated steam heated by the conductor tube 2 so that the deviation from the target temperature is less than ± 1 ° C. The temperature control unit 7 is a computer having a CPU, a memory, an input / output interface, and the like.

Therefore, the superheated steam generator 100 of the present embodiment includes a notification unit 8 that emits maintenance information using the operating temperature of the superheated steam generating unit 10, the operating time at the operating temperature, and the volume reduction rate at the operating temperature as parameters. Further prepared.

The notification unit 8 acquires the operating temperature data indicating the operating temperature of the superheated steam generating unit 10 and the operating time data indicating the operating time at the operating temperature, converts them into the operating time at a predetermined temperature, and integrates the integrated values. Is issued maintenance information when the predetermined integration threshold is exceeded. The notification unit 8 is a computer having a CPU, a memory, an input / output interface, and the like.

Specifically, the notification unit 8 uses the detection temperature data indicating the detection temperature of the temperature detector 5 or the target temperature data indicating the target temperature controlled by the temperature control unit 7 as the operating temperature data. Further, the notification unit 8 acquires operation time data indicating the operation time from its own timer or the timer of the temperature control unit 7. Then, the notification unit 8 uses these data to convert and integrate the operating time at 1200 ° C., and issues maintenance information when the integrated value exceeds a predetermined integration threshold value. The temperature of the conductor tube 2 may be used as the operating temperature data. In this case, the temperature detector is provided in contact with, for example, the lead port P2 of the conductor tube 2 or its vicinity. In particular, when the superheated steam generating unit 10 is in a standby state or when it is operated intermittently, it is desirable to use the temperature of the conductor tube 2.

The predetermined integrated threshold value is the volume reduction limit time, and is determined in advance by calculating from the pressure of superheated steam, the thermal expansion deformation value of the conductor tube 2, and the like. Further, the relationship between the volume reduction rate and the temperature is approximated by measuring several points (see FIG. 3), and from the detection temperature of the temperature detector 5 or the target temperature controlled by the temperature control unit 7. The volume reduction rate can be calculated from the detected temperature or the target temperature.

Here, a test operation is performed at the maximum temperature for each model of the superheated steam generator until the conductor tube is destroyed. This is because the fracture conditions differ depending on the curvature of the conductor tube, the flow velocity of superheated steam, and the amount of superheated steam generated.
For example, a model with a superheated steam generation amount of 60 kg / h and a superheated steam generation capacity of 1200 ° C., using an Inconel conductor tube (outer diameter Φ33.4 mm, inner diameter Φ26.64 mm, tube thickness t3.38 mm). A destructive test was conducted. The residual wall thickness of the broken maximum temperature part was 0.45 mm. The volume reduction rate characteristic after 1000 hours is shown in FIG. 2, and the reduction rate is represented by the formula y.

When operated for 1000 hours at a superheated steam temperature of 1200 ° C., the pipe thickness t is 1.4872 mm (decrease rate y ₁₂₀₀ = 0.56), which is a decrease of 1.8928 mm.
Assuming that the usage limit is 0.5 mm, the pipe thickness reduction value is 3.38-0.5 = 2.88 mm, and the arrival time T is T = 2.88 / (1.8928 / 1000) ≈1521 hours. Become.
Assuming that the rate of decrease in the operating temperature θ is y _θ and the operating time h _θ , the converted operating time h _{1200 at} 1200 ° C. is h ₁₂₀₀ = y _θ × h _θ / y ₁₂₀₀ .

For example, if the operating time at each temperature is 500 hours at 1200 ° C, 500 hours at 1100 ° C, and 500 hours at 1000 ° C, the operating time converted to 1200 ° C is as follows.
Conversion operation time h ₁₂₀₀ = 500+ (0.33 / 0.56) x 500+ (0.05 / 0.56) x 500 ≒ 840 hours

Then, when the converted operation time reaches a predetermined integration threshold value, maintenance information such as an alarm indicating the replacement time of the conductor tube 2 is issued.

Issuing maintenance information includes displaying a warning on a display, emitting a warning sound from a speaker, turning on or blinking a lamp such as an LED, and the like. It is also possible to set a predetermined integration threshold value in multiple stages and issue maintenance information in stages according to the converted operation time. Further, as maintenance information, the remaining time until the volume reduction limit time may be displayed on the display.

According to the superheated steam generator 100 configured in this way, maintenance information is issued with the operation time at the operating temperature as a parameter, so that the user can be informed of the maintenance time of the superheated steam generator 100, and the user can use the superheated steam generator. Maintenance can be performed before the conductor tube 2 or the like of the generator 100 fails.

The present invention is not limited to the above embodiment.
For example, the value calculated by the notification unit 8 for issuing maintenance information is not limited to the converted operation time of the embodiment, and is an integrated value of the product of the operation time at the operation temperature and the volume reduction rate at the operation temperature. You may use it.

Further, the notification unit 8 may issue maintenance information in consideration of only the operating temperature at which volume reduction is substantially a problem. Specifically, the notification unit 8 issues maintenance information using an operating temperature at which the volume reduction rate of the conductor tube 2 becomes a predetermined value (for example, 5%) or more when the conductor tube 2 is operated for a predetermined time as a parameter. For example, the notification unit 8 integrates the operation time of the operating temperature (1000 ° C. in the case of Inconel) or higher at which the volume reduction rate of the conductor tube 2 becomes, for example, 5% or more when the conductor tube 2 is operated for 1000 hours, and the integrated value is predetermined. Maintenance information is issued when the total threshold value of is exceeded.

Further, the notification unit 8 defines a temperature range used for maintenance information in the operating temperature of the superheated steam generating unit 10, and handles the operating time at the operating temperature included in the temperature range as the operating time at the maximum temperature in the temperature range. You may do so. For example, the temperature range used for maintenance information is defined as 900 to 1000 ° C, 1000 to 1100 ° C, and 1100 to 1200 ° C. Then, the notification unit 8 treats the operating time in the range of 900 to 1000 ° C. as the operating time of 1000 ° C. and accumulates it as the operating time of 1000 ° C. Similarly, the operating time in the range of 1000 to 1100 ° C. is treated as the operating time of 1100 ° C., and the operating time in the range of 1100 to 1200 ° C. is treated as the operating time of 1200 ° C.

Further, the temperature control unit 7 may acquire a signal indicating that the notification unit 8 has issued maintenance information, and may stop the operation of the superheated steam generation unit 10. The temperature control unit 7 and the notification unit 8 may be configured by the same computer.

In the above-described embodiment, the maintenance information indicating the replacement time of the conductor pipe 2 is issued, but even if the maintenance information indicating the replacement time of the external pipe connected to the outlet port P2 of the conductor pipe 2 is issued. good.

The notification unit may use the flow velocity (flow rate) of superheated steam flowing through the conductor tube 2 and the amount of superheated steam generated as parameters used for maintenance information. For example, the notification unit corrects the integrated value based on the amount of superheated steam generated by the superheated steam generating unit, and issues maintenance information when the corrected integrated value exceeds the integrated threshold value. When the superheated steam generation amount is used as a parameter, the notification unit may increase or decrease the operation time by using the measurement value of the measurement unit that measures the adjustment amount or the superheated steam generation amount by the steam amount adjustment mechanism. It is conceivable to increase the operating time accordingly when the generated amount is larger than the predetermined superheated water vapor amount, and decrease the operating time accordingly when the generated amount is smaller than the predetermined superheated water vapor amount. At this time, the notification unit corrects the operation time (integrated value) by using the relationship between the volume reduction rate and the flow velocity at each temperature (in the case of 1200 ° C., the volume reduction rate is proportional to 0.8 times the flow velocity). do.

Further, the notification unit may issue maintenance information using the wall thickness of the conductor tube as a parameter.

The superheated steam generating unit 10 may be of an energization heating method as well as an induction heating method. In this case, an AC power source or a DC power source is connected to both ends of the conductor tube 2 through which the fluid flows, and the conductor tube is heated by Joule by passing an AC current or a DC current through the conductor tube.

Further, as shown in FIG. 4, the superheated steam generator may be a combination of an induction heating method and an energization heating method. Specifically, the superheated steam generation unit 10 superheats generated by the first superheated steam generation unit 10A and the first superheated steam generation unit 10A of the induction heating method in which the conductor tube through which steam flows is induced and heated as a secondary coil. It has a second superheated steam generation unit 10B of an energization heating method in which a conductor tube through which steam flows is energized and heated to further heat superheated steam.

The first superheated steam generating unit 10A has the same configuration as that of the above embodiment. Further, the first superheated steam generation unit 10A is set to generate superheated steam of less than 1000 ° C. Further, the second superheated steam generating unit 10B has a conductor pipe 11 connected directly to the outlet port P2 of the conductor pipe 2 of the first superheated steam generating unit 10A or via an intermediate pipe. The conductor tube 11 is provided with a plurality of nozzles 11a for ejecting superheated steam. Power supply terminals 12 and 13 are provided at both ends of the conductor tube 11, and an AC power supply 17 is connected to the power supply terminals. When an electric current flows through the conductor tube 11 by this AC power source, the conductor tube generates Joule heat and the superheated steam flowing inside is heated.

In the superheated steam generator 100, the temperature of the superheated steam derived from the conductor tube 11 is detected by the temperature detector 14, and the control signal corresponding to the deviation between the detected temperature and the target temperature is sent to the voltage controller 15 (for example,). The AC voltage applied to the induction coil 32 by inputting to the thyristor) is controlled. Specifically, the temperature control unit 16 that performs this control feedback-controls the temperature of the superheated steam heated by the conductor tube 11 so that the deviation from the target temperature is less than ± 1 ° C. The temperature control unit 16 is a computer having a CPU, a memory, an input / output interface, and the like.

The notification unit 8 is provided on the side of the second superheated steam generation unit 10B, and as the operating temperature data, the detection temperature data indicating the detection temperature of the temperature detector 14 or the target temperature controlled by the temperature control unit 16 is used. The target temperature data shown is used. Further, the notification unit 8 acquires operation time data indicating the operation time from its own timer or the timer of the temperature control unit 16. Then, the notification unit 8 uses these data to convert and integrate the operating time at 1200 ° C., and when the integrated value exceeds a predetermined integration threshold value, an alarm indicating the replacement time of the conductor tube 11 is indicated. Issue maintenance information such as. The other functions of the notification unit 8 are the same as those in the above embodiment. In addition to the configuration of FIG. 4, the notification unit 8 may be provided on the first superheated steam generation unit 10A side to generate maintenance information indicating the replacement time of the body tube 2 as in the above embodiment. ..

In addition, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

100 ... Superheated steam generator 10 ... Superheated steam generator 2 ... Conductor tube 8 ... Notification unit

Claims (9)

An induction heating method or an energization heating type superheated steam generator that heats steam to generate superheated steam,
It is equipped with a notification unit that emits maintenance information using the operating temperature of the superheated steam generating unit and the operating time at the operating temperature as parameters.
The notification unit acquires operating temperature data indicating the operating temperature of the superheated steam generating unit and operating time data indicating the operating time at the operating temperature, converts them into operating hours at a predetermined temperature, and integrates the integrated values. When the predetermined integration threshold is exceeded, the maintenance information is issued, the integrated value is corrected based on the amount of superheated steam generated by the superheated steam generating unit, and the corrected integrated value is the integrated value. A superheated steam generator that emits the maintenance information when the threshold value is exceeded. The notification unit is for integration in terms of operating time at 1200 ° C., superheated steam generating apparatus according to claim 1, wherein. An induction heating method or an energization heating type superheated steam generator that heats steam to generate superheated steam,
It is equipped with a notification unit that emits maintenance information using the operating temperature of the superheated steam generating unit and the operating time at the operating temperature as parameters.
The superheated steam generating unit has a conductor tube through which the superheated steam flows.
The notification unit emits maintenance information indicating the replacement time of the conductor tube.
The notification unit is a superheated steam generator that emits maintenance information with an operating time at an operating temperature at which the volume reduction rate of the conductor tube becomes a predetermined value or more when the conductor tube is operated for a predetermined time as a parameter. The notification unit defines a temperature range used for maintenance information in the operating temperature of the superheated steam generating unit, and handles the operating time at the operating temperature included in the temperature range as the operating time at the maximum temperature in the temperature range. The superheated steam generator according to any one of claims 1 to 3. The superheated steam generator is
The first superheated steam generator of the induction heating method that induces and heats the conductor tube through which steam flows as a secondary coil,
Any of claims 1 to 4 having a second superheated steam generation unit of an energization heating method in which a conductor tube through which superheated steam generated by the first superheated steam generation unit flows is energized and heated to further heat the superheated steam. The superheated steam generator according to item 1. The superheated steam generator according to claim 5 , wherein the notification unit emits maintenance information indicating a replacement time of the conductor tube of the second superheated steam generating unit. The first superheated steam generating unit generates superheated steam of less than 1000 ° C.
The superheated steam generator according to claim 5 or 6 , wherein the second superheated steam generating unit generates superheated steam of 1000 ° C. or higher. It is a maintenance method of an induction heating method or an energization heating type superheated steam generator that heats steam to generate superheated steam.
Maintenance information is issued with the operating temperature of the superheated steam generator and the operating time at the operating temperature as parameters .
The operating temperature data indicating the operating temperature of the superheated steam generator and the operating time data indicating the operating time at the operating temperature are acquired, converted into the operating time at the predetermined temperature and integrated, and the integrated value is the predetermined integration threshold. When the value is exceeded, the maintenance information is issued, the integrated value is corrected based on the amount of superheated steam generated by the superheated steam generator, and the corrected integrated value exceeds the integrated threshold value. A method for maintaining a superheated steam generator that issues the maintenance information when the temperature is high. It heats steam to generate superheated steam, and is a maintenance method for an induction heating method or an energization heating type superheated steam generator having a conductor tube through which the superheated steam flows.
Maintenance information indicating the replacement time of the conductor tube is issued with the operating temperature of the superheated steam generator and the operating time at the operating temperature as parameters.
A maintenance method for a superheated steam generator that emits maintenance information using an operating time at an operating temperature at which the volume reduction rate of the conductor tube becomes a predetermined value or more when operated for a predetermined time as a parameter.

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