JP2016200413A - Wetness measuring system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wetness measuring system and method that can measure the wetness of steam without processing piping.SOLUTION: A wetness measuring system 1 comprises: a preheater 11 attached to an outer peripheral surface of piping P; a temperature measuring unit 13 attached to an outer peripheral surface of the piping P downstream of the preheater 11; and a preheater control device 17 that refers to the temperature measured by the temperature measuring unit 13, and controls the preheater 11 so that the entire moisture of the steam evaporates; and a data processing device 20 that finds the wetness of the steam flowing in the piping P on the basis of first information indicating the flow rate of steam flowing in the piping P and second information indicating the output of the preheater 11 controlled by the preheater control device 17.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wetness measurement system and method.

  In plants and factories, steam is widely used for overheating in production processes, heating / humidification in air conditioning, and other various uses. In order to efficiently supply steam used for such a wide range of applications, for example, boilers that generate steam are centrally installed in plants and the like, and steam generated by the boiler is connected by piping extending from the boiler. A steam supply system that leads to each part (site that requires steam) is provided. In a plant or the like equipped with such a steam supply system, it is indispensable to measure the flow rate and wetness (or dryness) of steam in order to “visualize” energy.

  Patent Document 1 below discloses a conventional technique for measuring the dryness of steam and determining the flow rate of saturated steam in the steam. Specifically, in Patent Document 1 below, the dryness of steam is measured based on the received light intensity of light transmitted through the steam, the mass flow rate of the steam is measured, and the mass of the saturated steam is measured based on these measurement results. A conventional technique for calculating a flow rate and calculating a flow rate of saturated steam based on the calculated mass flow rate of saturated steam is disclosed.

JP 2014-81214 A

  By the way, the prior art disclosed in Patent Document 1 described above measures the dryness of the vapor based on the received light intensity of the light transmitted through the vapor. For this reason, in order to measure the dryness of the vapor | steam which distribute | circulates the existing piping using the prior art disclosed by the patent document 1 mentioned above, a plant etc. are stopped and piping is processed (for example, drilling). It is necessary to install a device that measures the dryness by performing the above. Here, it is difficult to provide the above-described apparatus in consideration of the cost required for processing the piping in addition to the loss caused by stopping the plant.

  This invention is made | formed in view of the said situation, and it aims at providing the wetness measurement system and method which can measure the wetness of a vapor | steam, without processing piping.

In order to solve the above problems, the wetness measurement system of the present invention is attached to the outer peripheral surface of the pipe in the wetness measurement system (1, 2) for measuring the wetness of steam flowing in the pipe (P). With reference to the temperature measured by the temperature measurement unit, the temperature measurement unit (13) attached to the outer peripheral surface of the pipe downstream from the preliminary heating unit, A control unit (17) for controlling the preheating unit so that all the moisture of the vapor evaporates, first information indicating a flow rate of the steam flowing through the pipe, and the preheating controlled by the control unit And a calculation unit (20) for obtaining a wetness degree of the steam flowing through the pipe based on the second information indicating the output of the unit.
In addition, the wetness measurement system of the present invention includes a flow meter (12, 14, 15) that is provided on the downstream side of the preheating unit and measures the flow rate of steam flowing through the pipe, The calculation unit obtains the first information from the measurement result of the flow meter.
Alternatively, in the wetness measurement system of the present invention, the calculation unit calculates the first information by calculation based on a supply amount of fuel per unit time to a steam generation device (E1) that generates steam flowing through the pipe. It is characterized by calculating.
The wetness measurement system of the present invention is characterized in that the temperature measurement unit is attached in the vicinity of the preheating unit.
Further, the wetness measurement system of the present invention is characterized in that the temperature measurement unit is attached to a bottom portion of the outer peripheral surface of the pipe.
In the wetness measurement system of the present invention, the control unit controls the preheating unit so that the temperature measured by the temperature measurement unit is constant.
In the wetness measurement system of the present invention, the controller may be configured such that the temperature measured by the temperature measurement unit is higher than the saturated steam temperature in the pipe by a predetermined temperature. It is characterized by controlling the heating unit.
The wetness measurement method of the present invention is a wetness measurement method for measuring the wetness of steam flowing through the pipe (P), and is downstream of the preheating unit (11) attached to the outer peripheral surface of the pipe. The first step of measuring the temperature by the temperature measuring unit (13) attached to the outer peripheral surface of the pipe on the side and the temperature measured by the temperature measuring unit are referred to so that all the moisture of the vapor evaporates. Based on a second step of controlling the preheating unit, first information indicating a flow rate of steam flowing through the piping, and second information indicating an output of the controlled preheating unit. And a third step for determining the wetness of the steam circulating in the interior.
Further, the wetness measurement method of the present invention is characterized in that the first information is obtained from a measurement result of a flow meter that is provided on the downstream side of the preheating unit and measures the flow rate of steam flowing through the pipe. It is said.
Alternatively, the wetness measurement method of the present invention calculates the first information by calculation based on a supply amount of fuel per unit time to a steam generation device (E1) that generates steam flowing through the pipe. It is a feature.
The wetness measurement method of the present invention is characterized in that the second step is a step of controlling the preheating unit so that the temperature measured by the temperature measurement unit is constant.

  According to the present invention, the preheating unit is provided on the outer peripheral surface of the pipe, and the temperature measured by the temperature measuring unit attached to the outer peripheral surface of the pipe on the downstream side of the preheating unit is referred to. Since the preheating unit is controlled so as to evaporate, there is an effect that the wetness of the steam can be measured without processing the pipe.

It is a figure which shows the principal part structure of the wetness measuring system by 1st Embodiment of this invention. It is sectional drawing which shows the specific structure of the temperature measurement part of the wetness measuring system by 1st Embodiment of this invention. It is a block diagram which shows the principal part structure of the data processor with which the wetness measuring system by 1st Embodiment of this invention is provided. It is a figure which shows the attachment position of the temperature measurement part in the wetness measurement system by 1st Embodiment of this invention. It is a figure which shows the measurement result at the time of attaching a temperature measurement part to each of the attachment position shown in FIG. It is a figure which shows the other measurement result of the wetness measuring system by 1st Embodiment of this invention. It is a figure which shows the principal part structure of the wetness measuring system by 2nd Embodiment of this invention.

  Hereinafter, a wetness measurement system and method according to an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram showing a main configuration of a wetness measurement system according to a first embodiment of the present invention. As shown in FIG. 1, the wetness measurement system 1 of the present embodiment includes a preheater 11 (preheating unit), a measurement heater 12 (flow meter), a temperature measurement unit 13, temperature measurement units 14 and 15 (flow meter), It includes a pressure gauge 16, a preheater control device 17 (control unit), a heater power supply 18, a data collection device 19, and a data processing device 20 (calculation unit), and is disposed between the steam generation device E1 and the load facility E2. The wetness of the thermal fluid (for example, steam) flowing in the pipe P to be measured is measured.

  Here, the steam generation apparatus E1 is, for example, a boiler, and generates steam by heat obtained by burning fuel supplied from the outside. In this embodiment, in order to facilitate understanding, it is assumed that the steam generated by the steam generating device E1 is water vapor. The load facility E2 is a facility that uses the steam generated by the steam generation apparatus E1 and sent via the pipe P or the heat of the steam. Note that the steam discharged from the load facility E2 is collected as a drain, collected in a return water tank (not shown), and then supplied again to the steam generating device E1. Moreover, as the piping P, a carbon steel pipe (STPG) for pressure piping and a stainless steel pipe (SUS) can be used.

  The preheater 11 is attached to the outer peripheral surface of the pipe P upstream of the measurement heater 12 and heats the pipe P upstream of the measurement heater 12. The preheater 11 is provided to preheat the steam generated by the steam generating device E1 before the steam is input to the measuring heater 12. The reason why such a preheater 11 is provided is that the moisture contained in the steam is evaporated in advance, so that the flow rate can be measured with high accuracy even if the steam has a high wetness.

  The preheater 11 is, for example, an electric heater, and is wound around the outer peripheral surface of the pipe P at a constant pitch so as to heat the pipe P uniformly. Here, the length around which the preheater 11 is wound (the length of the pipe P in the pipe axis direction) is, for example, about 1 to several meters. As described above, the preheater 11 is provided to evaporate the moisture contained in the steam flowing in the pipe P, so that the length necessary for evaporating the moisture is ensured. The preheater 11 may be a ceramic heater. If a ceramic heater that breaks into two parts of a semicircle is used, it can be easily attached to the pipe P.

  The measurement heater 12 is attached to the outer peripheral surface of the pipe P downstream of the preheater 11 and heats the pipe P downstream of the preheater 11. This measuring heater 12 forms a part of a flow meter that measures the flow rate of the steam flowing in the pipe P from the temperature distribution in the pipe axis direction outside (outer peripheral surface) of the pipe P.

  The measurement heater 12 is an electric heater, for example, like the preheater 11, and is wound around the outer peripheral surface of the pipe P at a constant pitch so as to heat the pipe P uniformly. Here, the length in which the measurement heater 12 is wound (the length of the pipe P in the tube axis direction) is, for example, about 1 to several centimeters, and is shorter than the length in which the preheater 11 is wound. Is set to This is because it is sufficient that the temperature distribution necessary for measuring the flow rate of the steam flowing in the pipe P can be formed by the measuring heater 12. Note that the measurement heater 12 may also be a ceramic heater in the same manner as the preheater 11.

  The temperature measurement unit 13 is attached to the outer peripheral surface of the pipe P between the preheater 11 and the measurement heater 12 and measures the surface temperature of the pipe P. Specifically, the temperature measurement unit 13 is attached to the downstream side of the preheater 11 and in the vicinity of the preheater 11. For example, the temperature measurement unit 13 is attached to a position about 10 centimeters downstream from the end (downstream end) of the preheater 11. The reason why the temperature measuring unit 13 is attached at such a position is to effectively evaporate moisture contained in the steam flowing in the pipe P. The details of the mounting position of the temperature measuring unit 13 will be described later.

  Moreover, the temperature measurement part 13 is attached to the bottom part at least in the outer peripheral surface of the piping P in said position. The reason for such attachment is to effectively evaporate moisture contained in the steam flowing in the pipe P. For example, in the case where the temperature measuring unit 13 is attached only to the side portion on the outer peripheral surface of the pipe P, the temperature drop due to water droplets generated at the bottom of the inner peripheral surface of the pipe P is measured with a delay. In some cases, moisture contained in the steam flowing in the pipe P cannot be effectively evaporated.

  The temperature measurement unit 14 is attached to the outer peripheral surface of the pipe P upstream of the measurement heater 12 and downstream of the temperature measurement unit 13, and measures the surface temperature of the pipe P. The temperature measurement unit 15 is attached to the outer peripheral surface of the pipe P on the downstream side of the measurement heater 12 and measures the surface temperature of the pipe P. These temperature measuring units 14 and 15 form part of the above-described flow meter, and are provided to measure the temperature distribution on the surface of the pipe P in the pipe axis direction.

  The pressure gauge 16 is attached to the downstream side of the measurement heater 12 and measures the pressure of the steam flowing in the pipe P. The pressure gauge 16 may be attached to the downstream side of the measurement heater 12 as shown in FIG. 1 or may be attached to the upstream side of the preheater 11, and between the preheater 11 and the measurement heater 12. It may be attached to. A plurality of pressure gauges 16 may be provided. For example, the upstream side of the preheater 11 and the downstream side of the heater 12 for measurement.

  FIG. 2 is a cross-sectional view showing a specific configuration of the temperature measurement unit of the wetness measurement system according to the first embodiment of the present invention. 2A is a cross-sectional view in the direction along the pipe axis direction of the pipe P, and FIG. 2B is a cross-sectional view in the direction orthogonal to the pipe axis direction of the pipe P (FIG. 2A). It is an AA line cross-sectional arrow view in the inside. As shown in FIG. 2 (a), the temperature measurement unit 13 is positioned in the circumferential direction of the outer peripheral surface of the pipe P at a position separated from the end of the preheater 11 by a predetermined distance (for example, a position about 10 centimeters downstream). , Four temperature sensors 13a (for example, thermocouples) disposed so as to be different in positions by 90 degrees.

  The temperature measurement unit 14 includes a plurality of sensor groups (six sensor groups in the example illustrated in FIG. 2) arranged along the pipe axis direction of the pipe P on the upstream side of the measurement heater 12. Each sensor group provided in the temperature measurement unit 14 includes four temperature sensors 14a (for example, thermocouples) arranged so as to be shifted by 90 degrees in the circumferential direction of the outer peripheral surface of the pipe P. In addition, the sensor group provided in the temperature measurement part 14 may be arranged at equal intervals along the pipe-axis direction of the piping P, and may be arranged at unequal intervals. Normally, the temperature distribution in the tube axis direction in the vicinity of the measurement heater 12 is large, and the temperature distribution decreases as the distance from the measurement heater 12 decreases. Therefore, the sensor group included in the temperature measurement unit 14 is also close to the measurement heater 12 in close proximity. It is desirable to arrange and arrange sparsely as the distance from the measuring heater 12 decreases.

  The temperature measurement unit 15 includes a plurality of sensor groups (six sensor groups in the example shown in FIG. 2) arranged along the pipe axis direction of the pipe P on the downstream side of the measurement heater 12. Each sensor group provided in the temperature measurement unit 15 is arranged so that its position is different by 90 degrees in the circumferential direction of the outer peripheral surface of the pipe P, similarly to each sensor group provided in the temperature measurement unit 14. Two temperature sensors 15a (for example, thermocouples) are provided. In addition, the sensor group provided in the temperature measurement unit 15 may be arranged at equal intervals along the pipe axis direction of the pipe P, similarly to the sensor group provided in the temperature measurement unit 14, or may be arranged at unequal intervals. May be. Normally, the temperature distribution in the tube axis direction in the vicinity of the measurement heater 12 is large, and the temperature distribution decreases as the distance from the measurement heater 12 decreases. Therefore, the sensor group included in the temperature measurement unit 15 is also close to the measurement heater 12 in close proximity. It is desirable to arrange and arrange sparsely as the distance from the measuring heater 12 decreases.

  As described above, the plurality of temperature sensors 14 a are provided in each of the sensor groups of the temperature measurement unit 14, and the plurality of temperature sensors 15 a are provided in each of the sensor groups of the temperature measurement unit 15. Is obtained as a measured value, and an average value of a plurality of temperature sensors 15a is obtained as a measured value. Thus, by obtaining an average value as a measured value, a highly reliable measurement result can be obtained. In addition, as shown in FIG. 2, at least a part of the surface of the pipe P is covered with the heat insulating material H.

  The preheater control device 17 refers to the temperature (average value) measured by the temperature measurement unit 13 and controls the preheater 11 so that all the moisture of the vapor input into the preheater 11 evaporates. For example, the preheater control device 17 performs feedback control of the preheater 11 by performing PID (proportional integral derivative) control so that the measurement result of the temperature measurement unit 13 is constant. Here, the preheater control device 17 is configured such that the temperature measured by the temperature measuring unit 13 is higher than the saturated steam temperature in the pipe P by a predetermined temperature (for example, a temperature higher by about several to tens of degrees Celsius). The preheater 11 is controlled so that it becomes. This temperature is set so that all the moisture of the steam input into the preheater 11 can be evaporated.

  In addition, by setting the temperature to be controlled to a temperature that is higher by several to tens of degrees Celsius than the saturated steam temperature, as described later, even if steam with high wetness is input and the temperature drops, the saturated steam temperature or more is secured. This makes it easy to control the temperature. On the other hand, if the control target temperature is the saturated steam temperature (or a temperature slightly higher than the saturated steam temperature), the steam becomes a saturated steam temperature as soon as the steam with a high wetness is input and the temperature is lowered. It becomes difficult.

  The heater power supply 18 is a power supply that supplies power for heating the measurement heater 12 to the measurement heater 12. The data collection device 19 is a device that collects various data used in the wetness measurement system 1. Specifically, the data collection device 19 includes data indicating the measurement results of the temperature measuring units 13 to 15 and the pressure gauge 16, data relating to the control of the preheater 11 (the voltage applied to the preheater 11 and the current flowing through the preheater 11. Data) and data of the heater power supply 18 (data indicating the voltage applied to the measurement heater 12 and the current flowing through the measurement heater 12). As the data collection device 19, a so-called data logger device can be used.

  The data processing device 20 obtains the wetness of the steam flowing in the pipe P using the data collected by the data collecting device 19. Specifically, the data processing device 20 indicates that, from the data indicating the measurement results of the temperature measuring units 14 and 15, if the flow velocity is fast (the flow rate is large), the temperature distribution in the tube axis direction becomes small, and conversely the flow velocity is slow (flow rate). The flow rate (first information) is calculated in consideration of the fact that the temperature distribution in the tube axis direction increases. And the data processor 20 calculates | requires the wetness degree of the vapor | steam which flows in the inside of the piping P using the calculated flow volume and the data (2nd information) concerning control of the preheater 11. FIG.

  FIG. 3 is a block diagram showing a main configuration of the data processing device provided in the wetness measurement system according to the first embodiment of the present invention. As illustrated in FIG. 3, the data processing device 20 includes an input unit 21, a data acquisition unit 22, a data processing unit 23, a memory 24, and a display unit 25. The data processing device 20 can be realized by a computer such as a personal computer.

  The input unit 21 includes an input device such as a keyboard and a pointing device, and inputs various instructions from the outside. The data acquisition unit 22 acquires various data collected by the data collection device 19 under the control of the data processing unit 23 based on an instruction input from the input unit 21. Based on the instruction input from the input unit 21, the data processing unit 23 obtains the wetness of the steam flowing in the pipe P using the various data acquired by the data acquisition unit 22 and the various data stored in the memory 24. .

  Specifically, the data processing unit 23 obtains a temperature distribution (temperature distribution in the tube axis direction of the outer peripheral surface of the pipe P) from data indicating the measurement results of the temperature measuring units 13 and 14, and based on this temperature distribution, the pipe P Find the flow rate of the steam flowing inside. Here, in-pipe heat transfer (ease of heat transfer from the inside in the radial direction of the pipe P to the outside) changes according to the flow velocity of the steam flowing in the pipe P, and changes in in-pipe heat transfer in the pipe P Along with this, there is a relationship that a temperature distribution of heat applied to the surface of the pipe P is generated. Using this relationship, the data processing unit 23 obtains the flow rate of the steam flowing in the pipe P from the temperature distribution in the pipe axis direction of the outer peripheral surface of the pipe P, and calculates the flow rate of the steam flowing in the pipe P from the obtained flow rate. Looking for.

  Further, the data processing unit 23 obtains the wetness of the steam flowing through the pipe P using the data related to the control of the preheater 11 and the obtained flow rate of the steam. Here, since the preheater 11 is controlled so that the temperature measured by the temperature measurement unit 13 is constant, for example, when steam with high wetness is input into the preheater 11, the moisture of the steam is reduced. The amount of heat that compensates for the temperature drop caused by the evaporation of the component is supplied from the preheater 11. In addition, since the temperature decrease increases with the amount of moisture, the amount of heat necessary to compensate for the temperature decrease also increases with the amount of moisture. Using this relationship, the data processing unit 23 uses the data related to the control of the preheater 11 (electric power supplied to the preheater 11) to determine the wetness of the steam.

Here, when the enthalpy of steam near the upstream end of the preheater 11 is h1, and the enthalpy of steam near the downstream end of the preheater 11 is h2, these enthalpies h1 and h2 are represented by the following (1). , (2) respectively.
h1 = h2- (W / G) (1)
h2 = H (P, T) (2)

  However, in the above equation (1), “G” is the flow rate of the steam flowing in the pipe P, and “W” is the electric power supplied to the preheater 11. In the above equation (2), “P” is the pressure of the steam flowing in the pipe P, “T” is the temperature in the vicinity of the downstream end of the preheater 11, and “H” is the pressure and temperature. Is a function of

Further, when the dryness of the steam flowing in the pipe P is x, the dryness x is expressed by the following equation (3). However, in the following (3), “X” is a function of enthalpy and pressure.
x = X (h1, P) (3)

Here, substituting the above equation (2) into the above equation (1) into the above equation (3) yields the following equation (4): x = X (H (P, T )-(W / G), P) (4)
From the above equation (4), the dryness x of the steam flowing in the pipe P is the power “W” supplied to the preheater 11, the flow rate “G” of the steam flowing in the pipe P, and the pressure of the steam flowing in the pipe P. It can be seen that “P” and the temperature “T” in the vicinity of the downstream end of the preheater 11 are used.

In addition, the relationship between the dryness x and the wetness y of the steam which flows in the piping P has the relationship shown to the following (5) formulas.
y [%] = 100 [%]-x [%] (5)
Therefore, the wetness y of the steam flowing in the pipe P is also the electric power “W” supplied to the preheater 11, the flow rate “G” of the steam flowing in the pipe P, the pressure “P” of the steam flowing in the pipe P, and The temperature “T” in the vicinity of the downstream end of the preheater 11 can be used. The data processing unit 23 obtains the wetness y of the steam flowing in the pipe P using the equations (4) and (5).

  The memory 24 is, for example, a volatile or non-volatile memory (semiconductor memory), and stores various data necessary for determining the wetness of the steam flowing in the pipe P. For example, data in which the flow rate of the steam flowing through the pipe P and the temperature distribution in the pipe axis direction of the outer peripheral surface of the pipe P are stored is stored. The display unit 25 includes, for example, a display device such as a liquid crystal display device, and displays the wetness of the steam flowing through the pipe P obtained by the data processing unit 23. As described above, in the data processing unit 23, since the flow rate of the steam flowing in the pipe P is obtained, the flow rate of the steam may be displayed on the display unit 25.

  Next, the attachment position of the temperature measurement unit 13 will be described in detail. FIG. 4 is a diagram showing an attachment position of the temperature measurement unit in the wetness measurement system according to the first embodiment of the present invention. The attachment position specified by reference numeral X1 in FIG. 4 is a position about 20 centimeters downstream from the end of the preheater 11 (end on the downstream side), and the attachment position specified by reference X2 in FIG. Is a position about 10 cm downstream from the same end. Moreover, the attachment position specified by the code | symbol X3 in FIG. 4 is a position (position inside the preheater 11) about 10 centimeters upstream from the end part. The inner diameter of the pipe P is about 5 centimeters.

  Moreover, FIG. 5 is a figure which shows the measurement result at the time of attaching a temperature measurement part to each of the attachment position shown in FIG. Specifically, FIG. 5A shows a temperature sensor 13a used for control (a temperature sensor 13a attached to the bottom of the outer peripheral surface of the pipe P) at the attachment position X1 in FIG. 4, and FIG. 5B shows the same temperature. The sensor 13a is attached to the attachment position X2 in FIG. 4, and FIG. 5C is a diagram showing the measurement results when the temperature sensor 13a is attached to the attachment position X3 in FIG. The temperatures T shown in the graphs of FIGS. 5A to 5C are the temperatures at the attachment position X1, respectively (the average of the temperatures detected by the temperature sensors 13a attached to the right and left sides of the pipe P). Value), which is quite close to the temperature of the steam flowing into the measurement heater 12. Further, the power consumption W shown in each graph of FIGS. 5A to 5C is the power consumption of the preheater 11.

  The measurement results shown in FIG. 5 show that a carbon steel pipe for pressure piping having an inner diameter of about 5 centimeters and a thickness of about 5 millimeters is used as the piping P, and the flow velocity of the steam flowing in the piping P is 10 [cm / s. ] Is obtained in the case of the degree. The interval between the preheater 11 and the measurement heater 12 is set to about 45 centimeters, and any of the attachment positions X1 to X3 of the temperature measurement unit 13 shown in FIG. Is the position.

  First, referring to FIG. 5A, the curve T indicating the measurement result of the temperature measurement unit 13 pulsates at a constant cycle, and the curve W indicating the power consumption of the preheater 11 varies greatly in the same cycle. I understand that. This is because the attachment position X1 of the temperature measuring unit 13 is too far from the pre-heater 11, and thus a control delay due to a detection delay of a temperature drop (temperature drop caused by evaporation of moisture) occurs. Conceivable.

  Next, referring to FIG. 5B, it can be seen that the curve T indicating the measurement result of the temperature measurement unit 13 is substantially constant, and the change in the curve W indicating the power consumption of the preheater 11 is slight. This is because the mounting position X2 of the temperature measuring unit 13 is an appropriate position with respect to the preheater 11, and thus the temperature drop is detected at an appropriate timing, and the PID control of the preheater 11 is also appropriately performed. This is probably because of this.

  Subsequently, referring to FIG. 5 (c), the curve T indicating the measurement result of the temperature measurement unit 13 is gently changing, and the curve W indicating the power consumption of the preheater 11 is changing in a fine cycle. I understand. This is because the mounting position X3 of the temperature measuring unit 13 is set inside the preheater 11, so that a slight temperature change of the preheater 11 is measured immediately, and the preheater 11 is controlled based on this measurement result. It is thought that this is because.

  FIG. 6 is a diagram showing another measurement result of the wetness measurement system according to the first embodiment of the present invention. In addition, the curve to which the code | symbol T1 was attached | subjected in FIG. 6 is a curve which shows the measurement result of the temperature sensor 13a provided in the bottom part of the piping P in the attachment position X2 shown in FIG. Moreover, the curve to which the code | symbol T2 was attached | subjected in FIG. 6 is a curve which shows the measurement result of the temperature sensor 13a provided in the side part of the piping P in the attachment position X1 shown in FIG.

  As shown in FIG. 6, until time t1 (time when steam with high wetness is input to the preheater 11), the measurement result (see curve T1) of the temperature sensor 13a provided at the bottom of the pipe P at the attachment position X2 is Although the temperature is 186 ° C., after time t1, the change rapidly decreases to about 178 ° C. and then gradually recovers to 186 ° C. The rapid decrease in the measurement result of the temperature sensor 13a is caused by evaporation of moisture contained in the steam, and the gradual increase in the measurement result of the temperature sensor 13a is supplied from the preheater 11 with an amount of heat to compensate for the temperature decrease. This is thought to be caused by

  On the other hand, the measurement result (see curve T2) of the temperature sensor 13a provided on the side of the pipe P at the attachment position X1 is a change in the measurement result of the temperature sensor 13a provided on the bottom of the pipe P at the attachment position X2. Regardless of this, it is almost constant 176 ° C. From the above, it can be seen that the preheater 11 is well controlled so that the temperature (average value) measured by the temperature measurement unit 13 is constant. The reason why the temperature of the curve T1 is higher than that of the curve T2 is that the mounting position X2 of the temperature sensor 13a is closer to the preheater 11 than the mounting position X1, and the heat generated by the preheater 11 is transmitted. It is done.

When the temperature sensor 13a used for control (the temperature sensor 13a attached to the bottom of the outer peripheral surface of the pipe P) is attached to the attachment position X2 in FIG. 4, measurement is performed at the attachment positions X2 and X3 in FIG. When the steam with high wetness is input, the temperature is lowered to some extent from the temperature shown below. On the other hand, the temperature measured in the attachment position X1 in FIG. 4 and the position downstream from the attachment position X1 was stable at the temperature shown below. However, the temperature shown below is the average value of the temperature detected by the temperature sensor 13a attached to the right side surface and the left side surface of the pipe P at each position.
・ Mounting position X1… about 176 ° C. ・ Mounting position X2—about 185 ° C. ・ Mounting position X3—about 222 to 225 ° C. ・ Position downstream of the mounting position X1—about 174 ° C.

  Next, a wetness measurement method by the wetness measurement system 1 in the above configuration will be described. Here, in order to simplify the description, it is assumed that the steam is generated by the steam generation device E1 and the generated steam is supplied to the load facility E2 via the pipe P. When the power of the wetness measurement system 1 is turned on, the temperature measurement unit 13 measures the temperature (first step), the temperature (average value) measured by the temperature measurement unit 13 is referred to, and the steam The preheater 11 is controlled by the preheater control device 17 so that all the moisture is evaporated (second step). For example, the temperature (average value) measured by the temperature measurement unit 13 is controlled to be constant.

  In parallel with the above operation, electric power is supplied from the heater power supply 18 to the measurement heater 12, and the pipe P is heated by the measurement heater 12. Here, since the steam from the steam generator E1 flows in the pipe P, the heat transfer in the pipe P changes. The temperature of the upstream side of the measuring heater 12 is measured by the temperature measuring unit 14, and the temperature of the downstream side of the measuring heater 12 is measured by the temperature measuring unit 15. The temperature distribution in the direction is measured.

  Data indicating the measurement results of the temperature measuring units 14 and 15 is collected by the data collecting device 19 and then acquired by the data acquiring unit 22 of the data processing device 20. Then, in the data processing unit 23, the temperature distribution in the tube axis direction of the outer peripheral surface of the pipe P is obtained, and the process for obtaining the flow rate of the steam flowing through the pipe P using the obtained temperature distribution is performed. The flow rate of the steam flowing in the pipe P is, for example, the temperature distribution in the tube axis direction of the outer peripheral surface of the pipe P and data stored in the memory 24 (the flow rate of the steam flowing in the pipe P and the pipe on the outer peripheral surface of the pipe P). It is obtained by comparing the temperature distribution with the temperature distribution in the axial direction.

  Data related to the control of the preheater 11 (data indicating the voltage applied to the preheater 11 and the current flowing through the preheater 11) and data indicating the measurement results of the temperature measuring unit 13 and the pressure gauge 16 are also collected by the data collecting device 19. Is acquired by the data acquisition unit 22 of the data processing device 20. Then, in the data processing unit 23, processing for obtaining the wetness of the steam flowing in the pipe P is performed using the above-described equations (4) and (5) (third step). When the above processing is completed, information indicating the wetness level of the steam is output to the display unit 25 and displayed.

  As described above, according to the present embodiment, the preheater 11 is provided on the outer peripheral surface of the pipe P upstream of the measurement heater 12 that forms part of the flow meter, and the pipe between the preheater 11 and the measurement heater 12 is provided. The preheater 11 is controlled by the preheater control device 17 so that the temperature measured by the temperature measuring unit 13 attached to the outer peripheral surface of P is constant. Then, the flow rate of the steam is obtained from the measurement results of the temperature measuring units 14 and 15, and the wetness of the steam flowing in the pipe P is obtained using the flow rate and data related to the control of the preheater 11. Thereby, the wetness of steam can be measured without processing the piping P.

[Second Embodiment]
FIG. 7 is a diagram showing a main configuration of a wetness measurement system according to the second embodiment of the present invention. In FIG. 7, the same components as those shown in FIG. As shown in FIG. 7, the wetness measurement system 2 of the present embodiment omits the measurement heater 12, the temperature measurement units 14 and 15, and the heater power supply 18 of the wetness measurement system 1 shown in FIG. It is the structure which added. The wetness measurement system 2 having such a configuration is capable of measuring the wetness of the steam without actually measuring the flow rate of the steam flowing through the pipe P.

  The flow meter 30 measures the flow rate of the fuel supplied from the outside to the steam generator E1. Here, the amount of heat per unit time generated by the combustion of the fuel supplied to the steam generator E1 is determined by the type of fuel and the amount of fuel supplied per unit time. The flow meter 30 is provided to obtain this heat quantity. Data indicating the measurement result of the flow meter 30 is collected by the data collection device 19 and acquired by the data acquisition unit 22 of the data processing device 20.

  The data processing device 20 shown in FIG. 7 has the same configuration as the data processing device 20 shown in FIG. 1 (configuration shown in FIG. 3), but the processing performed by the data processing unit 23 is different. Specifically, the data processing unit 23 of the data processing device 20 shown in FIG. 7 flows in the pipe P using data indicating the measurement result of the flow meter 30 (the flow rate of fuel supplied to the steam generation device E1). A process for obtaining the steam flow rate and the like and obtaining the wetness of the steam flowing in the pipe P from this flow rate is performed.

Here, when the amount of heat of the fuel supplied from the outside to the steam generator E1 is Qi and the amount of heat discharged from the steam generator E1 to the atmosphere is Qo, the efficiency of the steam generator E1 (boiler efficiency (loss method)) ) Η is defined by the following equation (6). It is known that the boiler efficiency by the loss method is (easily) obtained from boiler exhaust gas analysis or the like.
η = (Qi−Qo) / Qi × 100 [%] (6)

Moreover, when the calorie | heat amount of the vapor | steam produced | generated with the steam production | generation apparatus E1 is set to Qs, this calorie | heat amount Qs of steam is represented by the following (7) Formula.
Qs = Qi × η (7)
That is, the heat quantity Qs of the steam generated by the steam generation apparatus E1 is multiplied by the heat quantity Qi of the fuel supplied to the steam generation apparatus E1 (that is, the measurement result of the flow meter 30) and the efficiency η of the steam generation apparatus E1. Is required. The efficiency η of the steam generator E1 can be obtained in advance from a design value or an actual measurement value.

Moreover, the calorie | heat amount Qs produced | generated by the steam production | generation apparatus E1 is set to the following (8) Formula, when hs is the enthalpy of the water produced | generated by the production | generation of steam and h0 is set to h0. Also represented by
Qs = G × (hs−h0) (8)
In the above equation (8), “G” is the flow rate of the steam generated by the steam generating device E1 (the flow rate of the steam flowing in the pipe P).

  In the above equation (8), the variable “Qs” on the left side can be obtained from the above equation (7), and the variable “h0” on the right side can be obtained if the temperature of water used for generating steam is known. . Therefore, there are two unknown variables “G” and “hs” on the right side in the equation (8). The reason why the variable “G” is unknown is that the wetness measurement system 2 does not include a flow meter. In the above-described equation (1), the variable “h2” on the right side can be obtained from the above-described equation (2), and the variable “W” is the power supplied to the preheater 11. Then, there are two unknown variables in the above-described equation (1), the variable “h1” on the left side and the variable “G” on the right side.

  Thus, since the above-described equation (1) and the above equation (8) are equations having two unknown variables, if they are solved simultaneously, the flow rate of the steam generated by the steam generator E1 (Flow rate of steam flowing in the pipe P) can be obtained. When the flow rate of the steam flowing through the pipe P is obtained, the dryness x of the steam flowing in the pipe P can be obtained using the above-described equation (4), and the pipe using the above-described equation (5). The wetness of the steam flowing in P can be determined.

  Next, a wetness measurement method by the wetness measurement system 2 in the above configuration will be described. Here, in order to simplify the description, it is assumed that steam is generated by the steam generation device E1 and the generated steam is supplied to the load facility E2 via the pipe P. When the power of the wetness measurement system 1 is turned on, the temperature measurement unit 13 measures the temperature (first step), and the temperature (average value) measured by the temperature measurement unit 13 is constant. The preheater 11 is controlled by the preheater control device 17 (second step).

  In parallel with the above operation, the flow rate of the fuel supplied to the steam generator E1 is measured by the flow meter 30. Data indicating the measurement result is collected by the data collection device 19 and then acquired by the data acquisition unit 22 of the data processing device 20. Then, the process which calculates | requires the flow volume of the vapor | steam which flows in the piping P in the data processing part 23 is performed.

  Data related to the control of the preheater 11 (data indicating the voltage applied to the preheater 11 and the current flowing through the preheater 11) and data indicating the measurement results of the temperature measuring unit 13 and the pressure gauge 16 are also collected by the data collecting device 19. Is acquired by the data acquisition unit 22 of the data processing device 20. Then, in the data processing unit 23, processing for obtaining the wetness of the steam flowing in the pipe P is performed using the above-described equations (4) and (5) (third step). When the above processing is completed, information indicating the wetness level of the steam is output to the display unit 25 and displayed.

  As described above, according to the present embodiment, the preheater 11 is provided, the temperature measured by the temperature measurement unit 13 attached to the outer peripheral surface of the pipe P downstream of the preheater 11 is referred to, and all the moisture of the steam is present. The preheater 11 is controlled by the preheater control device 17 so as to evaporate. And the flow rate of the steam which flows through the piping P is calculated | required using the measurement result of the flowmeter 30, and the wetness degree of the steam which flows through the piping P is calculated | required using this flow rate and the data concerning control of the preheater 11. Yes. Thereby, the wetness of steam can be measured without processing the piping P.

  The wetness measurement system and method according to the embodiment of the present invention have been described above. However, the present invention is not limited to the above embodiment, and can be freely changed within the scope of the present invention. For example, in the above-described embodiment, the example of measuring the flow rate of the water vapor generated by the steam generation device E1 has been described. However, the present invention may be applied to the flow rate measurement of, for example, LNG (liquefied natural gas). it can.

  Moreover, although 1st Embodiment mentioned above demonstrated the example provided with the flowmeter which measures the flow volume of the steam which flows through the inside of piping P from the temperature distribution of the exterior (outer peripheral surface) of piping P, this invention is this flowmeter. In addition, a differential pressure flow meter using an orifice plate, an ultrasonic flow meter, a vortex flow meter, a flow meter using a curvature sensor, and other flow meters can be used. In the above-described embodiment, the example in which the pre-heater control device 17, the heater power source 18, the data collection device 19, and the data processing device 20 are provided as separate bodies has been described, but these are integrally provided. Also good.

  In the above-described embodiment, the configuration in which the preheater 11 and the measurement heater 12 provided in the pipe P are covered with the heat insulating material H has been described as an example, but the present invention is not limited thereto. For example, when the data processing device 20 performs processing for correcting data indicating the measurement results of the temperature measuring units 14 and 15 in consideration of heat radiation from the surface of the pipe P, the surface of the pipe P is kept warm. The material H may not be covered. Or the structure which coat | covers only a part of surface of the piping P (installation part of the temperature measurement parts 13-15) with the heat insulating material H may be sufficient.

DESCRIPTION OF SYMBOLS 1, 2 Wetness measuring system 11 Preheater 12 Heater for measurement 13 Temperature measurement part 14 Temperature measurement part 15 Temperature measurement part 17 Preheater control apparatus 20 Data processing apparatus E1 Steam generation apparatus P Piping

Claims (11)

In the wetness measurement system that measures the wetness of the steam flowing through the pipe,
A preheating unit attached to the outer peripheral surface of the pipe;
A temperature measurement unit attached to the outer peripheral surface of the pipe downstream from the preheating unit;
A control unit that refers to the temperature measured by the temperature measurement unit and controls the preheating unit so that all of the moisture of the vapor evaporates;
Based on the first information indicating the flow rate of the steam flowing through the pipe and the second information indicating the output of the preheating unit controlled by the control unit, the wetness of the steam flowing through the pipe is determined. A wetness measurement system comprising: a calculation unit to be obtained. Provided on the downstream side of the preheating unit, provided with a flow meter for measuring the flow rate of the steam flowing through the pipe,
The wetness measurement system according to claim 1, wherein the calculation unit obtains the first information from a measurement result of the flow meter.   2. The wetness according to claim 1, wherein the calculation unit calculates the first information by calculation based on a supply amount of fuel per unit time to a steam generation device that generates steam flowing through the pipe. Degree measurement system.   The wetness measurement system according to any one of claims 1 to 3, wherein the temperature measurement unit is attached in the vicinity of the preheating unit.   The said temperature measurement part is attached to the bottom part in the outer peripheral surface of the said piping, The wetness measuring system as described in any one of Claims 1-4 characterized by the above-mentioned.   The said control part controls the said preheating part so that the temperature measured by the said temperature measurement part may become constant, The wetness degree measurement as described in any one of Claims 1-5 characterized by the above-mentioned. system.   The said control part controls the said preheating part so that the temperature measured by the said temperature measurement part may become a temperature higher only by the temperature prescribed | regulated previously than the saturated steam temperature in the said piping. Item 7. The wetness measurement system according to item 6. A wetness measurement method for measuring the wetness of steam circulating in a pipe,
A first step of measuring the temperature with a temperature measuring unit attached to the outer peripheral surface of the pipe downstream from the preheating unit attached to the outer peripheral surface of the pipe;
A second step of referring to the temperature measured by the temperature measuring unit and controlling the preheating unit so that all of the moisture of the vapor evaporates;
A third step of obtaining the wetness of the steam flowing through the pipe based on the first information indicating the flow rate of the steam flowing through the pipe and the second information indicating the output of the controlled preheating unit. And a wetness measurement method characterized by comprising:   The wetness measurement method according to claim 8, wherein the first information is obtained from a measurement result of a flow meter that is provided downstream of the preheating unit and measures a flow rate of steam flowing through the pipe. .   The wetness measurement method according to claim 8, wherein the first information is calculated by calculation based on a supply amount of fuel per unit time to a steam generation device that generates steam flowing through the pipe.   The said 2nd step is a step which controls the said preheating part so that the temperature measured by the said temperature measurement part may become fixed, The any one of Claims 8-10 characterized by the above-mentioned. Wetness measurement method.

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