JP5251465B2 - Heat loss evaluation system and evaluation method for steam pipe - Google Patents

Description

  The present invention relates to a heat loss evaluation system and an evaluation method for a steam pipe.

  In the steam pipe through which the superheated steam flows, the enthalpy can be calculated based on the results of measuring the temperature, pressure, and flow rate at at least two positions. Therefore, the evaluation of heat loss is relatively easy.

  In a steam pipe through which saturated steam flows, when heat loss occurs, wet steam is generated, and therefore, it is relatively difficult to evaluate heat loss. 2. Description of the Related Art Conventionally, a method is known in which a pipe surface temperature is determined using a special device such as a thermography, and heat loss is analyzed and evaluated based on the pipe surface temperature. Alternatively, a method is known in which a steam flow rate is measured at the end of use of steam and heat loss is analyzed and evaluated based on the result.

  In the method using a special apparatus such as thermography, the measurement accuracy of the pipe surface temperature is not sufficient, the evaluation of the thermal conductivity of the steam pipe or the heat insulating material is relatively difficult, and the apparatus is expensive. Have

  In the method of measuring the steam flow rate at the end of use, it is necessary to install a specific flow meter using a differential pressure type velocimeter such as an orifice at the end of use. All the moisture (drain) is removed from the drain trap. Since it is not limited, there is a problem that the evaluation of wetness may be insufficient.

  An object of this invention is to provide the evaluation system and the evaluation method which can evaluate preferably the heat loss of a steam pipe.

According to an aspect of the present invention, there is provided a system for evaluating heat loss of a steam pipe, wherein a plurality of sections set in the steam pipe through which steam flows and at least one of pressure and temperature in the steam pipe are measured. One measuring device and a plurality of drain units each capable of discharging drain from the end points of the plurality of sections, each of the plurality of drain units each having a drain trap, a value related to a drain amount, and a drain temperature. A second measuring device that measures each of the drain units, and a calculation device that evaluates the heat dissipation loss of the steam pipe using the measurement result of the first measuring device and the measurement result of the second measuring device , the computing device, heat loss evaluation systems that evaluate the heat radiation loss of the steam pipe is provided with assumption capture ratio assuming a ratio of the drain to be trapped in the drain trap

  According to this evaluation system, the heat radiation loss of the steam pipe can be evaluated using the measurement result of the drain unit having the drain trap. Therefore, comparatively easy heat loss evaluation is realized.

According to another aspect of the present invention, there is provided a method for evaluating heat loss of a steam pipe, comprising a first measurement step of measuring at least one of pressure and temperature in the steam pipe through which steam flows, and a drain at each end point. For a plurality of sections set in the steam pipe provided with a trap, a second measurement step for measuring a drain amount and a value related to the drain amount via the drain trap, a measurement result of the first measurement step, and the first Heat loss including a calculation step of evaluating the heat dissipation loss of the steam pipe using a measurement result of two measurement steps, and a step of inputting an assumed trap rate assuming the proportion of drain trapped in the drain trap An evaluation method is provided.

  According to this evaluation method, the heat loss of the steam pipe can be evaluated using the value relating to the drain amount via the drain trap and the result of measuring the drain temperature. Therefore, comparatively easy heat loss evaluation is realized.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing a heat loss evaluation system 1. In FIG. 1, the steam pipe 10 is disposed between a steam generator 20 (such as a boiler) and a load facility 30. Steam from the steam generator 20 flows through the steam pipe 10 and is sent to the load facility 30. In the load facility 30, steam or steam heat is used. The steam pipe 10 is heat-retained by heat retention means (not shown). Various known heat retaining means can be applied. The heat retaining means includes, for example, a heat retaining material that covers the outer surface of the steam pipe 10.

  The steam pipe 10 is provided with a plurality of drain traps DT1, DT2, DT3,... DTn. At least a part of the drain generated by condensation in the steam pipe 10 is captured by the drain traps DT1, DT2, DT3,... DTn. Various known drain traps are applicable. Usually, the drain traps DT1, DT2, DT3,... DTn have a structure capable of appropriately discharging the trapped drain.

  As shown in FIG. 1, the heat loss evaluation system 1 includes at least one of sections SC1, SC2, SC3,..., SCn continuously set in the steam pipe 10 and the pressure and temperature in the steam pipe 10. Sensors (first measuring devices) PS1, PS2, PS3,... PSn and drain units DU1, DU2, DU3,... DUn having drain traps DT1, DT2, DT3,. And a control unit 40 including a computing device 50. In the present embodiment, the sensors PS1, PS2, PS3,... PSn measure the pressure in the steam pipe 10. Various known pressure sensors can be applied as the sensors PS1, PS2, PS3,... PSn. The measurement results from the sensors PS1, PS2, PS3,... PSn are sent to the control unit 40.

  The drain units DU1, DU2, DU3,... DUn can discharge the drain generated in the steam pipe 10 from the end points of the sections SC1, SC2, SC3,. As shown in FIG. 2, a part of the drain in the steam pipe 10 existing before the trap is trapped in the drain trap DTn. Other parts of the drain remain in the steam pipe 10 after trapping. Here, the ratio of the drain trapped by the drain trap DTn is referred to as a trap rate.

  FIG. 3 is a schematic diagram showing the drain unit DUn. As shown in FIG. 3, in addition to the drain trap DTn, the drain unit DUn includes a drain line 60, a temporary hose 62, a water receiving tank 64, a temperature sensor (second measuring device) 70, and a weigh scale (second measuring device) 80. Have The drain line 60 is a branch line of the steam pipe 10 and can have a pipe through which the drain from the steam pipe 10 flows. A drain trap DTn is disposed on the drain line 60.

  The temporary hose 62 is for guiding the drain from the drain trap DTn to the water receiving tank 64, and is connected to the drain trap DTn (or piping equipment disposed at the outlet end of the drain trap DTn). The temporary hose 62 can be detachably disposed with respect to the drain trap DTn. If the drain from the drain trap DTn is preferably guided directly to the water receiving tank 64, the temporary hose 62 can be omitted.

  The water receiving tank 64 stores the drain from the drain trap DTn. The water receiving tank 64 can have a structure that suppresses a decrease in the drain temperature and / or a structure that suppresses evaporation of the drain as necessary. The temperature sensor 70 can measure the temperature of the drain stored in the water receiving tank 64. Various known temperature sensors can be used as the temperature sensor 70. The measurement result from the temperature sensor 70 is sent to the control unit 40.

  At least a part of the drain unit DUn can be shared between the sections SC1, SC2, SC3,. For example, after being used for measurement in one section, at least one of the temporary hose 62, the water receiving tank 64, the temperature sensor 70, and the weight scale 80 can be used for measurement in another section.

  Returning to FIG. 1, the measurement of the drain flow rate and the drain temperature using the drain unit DUn can be performed in order of each of the sections SC1, SC2, SC3,. Alternatively, the measurement can be performed simultaneously in two or more of the sections SC1, SC2, SC3,. Selection and / or switching of measurement intervals can be performed automatically or manually using the control unit 40.

  FIG. 4 is a schematic diagram showing the control unit 40. In FIG. 4, the computing device 50 is, for example, a computer system. The control unit 40 includes an input device 127 and a display device (output device) 128 in addition to the calculation device 50. The computing device 50 includes a converter 123 such as an A / D converter, a CPU (arithmetic processing means) 124, a memory 125, and the like. Measurement data sent from the sensors of the heat loss evaluation system 1 (sensors PS1, PS2, PS3,... PSn, temperature sensor 70, weight scale 80, etc.) are converted by the converter 123 or the like as necessary. It is taken into the CPU 124. In addition, initial setting values, temporary data, and the like are taken into the computing device 50 via the input device 127 and the like. The display device 128 can display information regarding input data, information regarding calculation, and the like.

  Based on the measurement data and the information stored in the memory 125, the CPU 124 can execute a calculation related to the heat loss of the steam pipe. For example, the heat loss of the steam pipe 10 can be analyzed using the measurement results of the sensors PS1, PS2, PS3,... PSn, the temperature sensor 70, and the weight meter 80. Here, an example of the analysis method regarding the heat loss of the steam pipe 10 is shown below.

  In the system of the steam generation device 20 (for example, a boiler), the steam pipe 10, and the load facility 30 shown in FIG. 1, when the steam from the steam generation device 20 is saturated steam, the equations (1) and (2) Holds.

  Moreover, Formula (3) is formed from the relationship between the heat dissipation loss per unit area of the steam pipe 10 and the heat dissipation loss per unit length.

  From these, the steam flow rate at the position before the first drain trap DT1 (abbreviated as trap 1 as appropriate) (substantially end point of the first section SC1) and the position before the drain trap DT1 (substantially the section SC1). The drain flow rate at the target end point can be solved from the simultaneous equations of the following equations (4) and (5).

  The calculated drain flow rate (calculated drain amount) is calculated from the equation (6) using the drain trapping rate.

  In the drain unit DU1, the total amount of drain discharged from the drain trap DT1 and the drain temperature are obtained. In general, in the drain trap, it is known that a measured value (measured drain amount) of the drain flow rate can be obtained from the simultaneous equations of Expressions (7) and (8).

  Equations (9) and (10) can be derived from equations (7) and (8).

  Thus, from equation (6), the calculated drain flow rate (calculated drain amount) in the first drain trap DT1, and from equation (10), the measured drain flow rate (measured drain amount) in the first drain trap DT1. ) Can be calculated.

  Next, the steam flow rate at the position after the first drain trap DT1 (substantial start point of the second section SC2) and the drain flow rate at the position after the drain trap DT1 (substantially start point of the section SC2). Can be expressed using the following equations (11) and (12).

  By using the equations (11) and (12), the calculated value of the drain flow rate (calculated drain amount) in the second drain trap DT2 and the drain trap DT2 in the same manner as the calculation procedure from the equation (4). A measured value of the drain flow rate (measured drain amount) can be calculated.

  Here, the calculated value of Equation (6) uses an assumed heat dissipation loss assuming the heat dissipation loss of the steam pipe 10 per unit area and an assumed capture rate assuming the ratio of the drain trapped in the drain trap DT1. Can be obtained. It can be considered that the difference between the calculated drain amount value and the measured drain amount value is the smallest in the optimum value of the pair of the assumed heat dissipation loss and the assumed capture rate. Therefore, the heat loss in the first section SC1 of the steam pipe 10 is estimated by searching for a pair of the assumed heat dissipation loss and the assumed capture rate so that the difference between the calculated drain amount and the measured drain amount is small. Can do.

  Also for the second drain trap DT2, using Equation (11) and Equation (12), a pair of assumed heat dissipation loss and assumed capture rate that reduces the difference between the calculated drain amount and the measured drain amount is obtained. By searching, the heat dissipation loss in the second section SC2 of the steam pipe 10 can be estimated.

  In this way, in each drain trap DT1, DT2, DT3,... DTn, an optimum pair of assumed heat dissipation loss and assumed capture rate can be searched. Furthermore, it is possible to search for a pair of an assumed heat dissipation loss and an assumed capture rate such that the difference between the calculated value (calculated drain amount) and the measured value (measured drain amount) of the drain flow rate becomes the smallest overall.

  In this example, the assumed heat dissipation loss and the assumed capture rate are common among the drain traps DT1, DT2, DT3,... DTn. Therefore, the heat dissipation loss of the steam pipe 10 can be estimated by searching for a pair of the assumed heat dissipation loss and the assumed capture rate so that the difference between the calculated drain amount and the measured drain amount becomes the smallest overall.

  FIG. 5 is a flowchart showing a processing procedure relating to heat loss evaluation.

  In FIG. 5, first, initial values (such as the length of each section) regarding the system including the steam pipe 10 and assumed values regarding the heat dissipation loss and the capture rate are input to the calculation device 50 (steps 101 and 102). The assumed value that is input first may be empirical reference data or random data. For example, as a guide, an assumed heat dissipation loss per unit area of 12-13 W / m2 / K and an assumed trap rate of a drain trap of 70% can be used.

  In a predetermined section SCn of the steam pipe 10, the sensor PSn measures the pressure (or temperature) in the steam pipe 10. Further, in the drain unit DUn, the temperature sensor 70 and the weight meter 80 measure the total amount of drain discharged from the drain trap DTn and the drain temperature. The calculation device 50 can calculate a calculated value (calculated drain amount) of the drain flow rate in the drain trap DTn using the input initial value, assumed value, measurement data, and the like (step 103).

  Further, the calculation device 50 can calculate the measured value (measured drain amount) of the drain flow rate in the drain trap DTn using the input initial value, measurement data, and the like (step 104).

  From the measured drain amount data and the plurality of calculated drain amount data, the calculation device 50 can perform the optimum state evaluation (step 105). For example, the value of another drain flow rate (calculated drain amount) can be calculated by inputting the shifted assumed value. A plurality of calculated drain amounts are calculated for the drain trap DTn based on the plurality of assumed values. The calculation device 50 compares the calculated drain amount with the measured drain amount with respect to the drain traps DT1, DT2, DT3,... DTn, and assumes the assumed heat dissipation loss and the assumed trap so that the difference between them becomes the smallest overall. Search for the best pair of rates. By such optimal state evaluation, the heat dissipation loss of the steam pipe 10 can be estimated.

  For comparison between the calculated drain amount and the measured drain amount, a simple difference (or ratio) may be used, or an existence probability may be used.

  The normal distribution is expressed by equation (13).

  The overall probability f (w, C) is the product of the probability density function fn (w, C) of each drain trap and is expressed as in equation (14).

  As described above, in this embodiment, the heat loss of the steam pipe is reduced using the measurement results of the drain units DU1, DU2, DU3,... DUn having the drain traps DT1, DT2, DT3,. Can be evaluated. As the drain traps DT1, DT2, DT3,... DTn, those already installed can be used. Sensors PS1, PS2, PS3,... PSn can also be used already installed. Therefore, in the present embodiment, it is possible to estimate the heat loss relatively easily without newly processing the steam pipe 10.

  In the present embodiment, more accurate estimation of heat loss is possible by using the assumed trap rate assuming the rate of drain trapped in the drain traps DT1, DT2, DT3,... DTn. In other words, not only the assumed heat loss but also the calculation result of the heat loss is led to the optimum value by the combination of the assumed capture rate and the optimum state evaluation method.

  By using a statistical method, an optimal pair solution can be estimated from a plurality of data. Estimates and tests can also be performed using probability distributions (normal distribution, t distribution, etc.) based on applied mathematics techniques. By finding numerical properties, regularity, or irregularity, it is possible to make a more accurate estimation or detect an abnormal value.

  Statistical outliers can be used to detect drain trap failures and partial heat leaks. In the present embodiment, a common assumed heat dissipation loss and assumed capture rate are used, but the present invention is not limited to this. Based on the result of the trend analysis, the assumed heat dissipation loss and the assumed capture rate can be weighted for a specific section.

  Additionally or alternatively, more output can be taken by changing the output from the steam generator 20. More accurate estimation is possible by collecting data under various conditions.

  In the present embodiment, the display device 128 of the control unit 40 can display the calculation result and the calculation process of the heat loss. The display device 128 can also display the data distribution as a scatter diagram or a correlation diagram. Visual trend analysis allows visual verification of heat loss calculation results.

  Next, another example of the analysis method regarding the heat loss of the steam pipe 10 will be described below. In the present example, in addition to the assumed capture rate, the assumed wetness assuming the wetness (1-dryness) of the steam entering the steam pipe 10 is used.

In the following,
d: diameter of steam pipe [m],
G: Flow rate [kg / s],
h: Enthalpy [J / kg],
L: tube length [m],
C: Drain trapping rate [−] in the drain trap,
r: pipe radius [m],
T: temperature [° C.]
v: Flow velocity [m / s],
W: calorie [W],
X: Dryness [−],
δ: deviation [−],
θ: insulation thickness [m]
λ: thermal conductivity [W / m / K],
σ: variance [−],
boiler_out: boiler exit,
catch: catch drain,
critical: critical,
drain: drain,
measure: measured value,
n: Trap order,
out: exterior,
rad: heat dissipation,
sat_l: saturated solution,
sat_v: saturated steam,
theory: Theoretical formula,
v: steam,
X: dryness,
It is.

  The heat radiation amount of the steam pipe up to the first drain trap DT1 of the steam pipe 10 can be calculated as in Expression (15).

  The drain flow rate before the first drain trap DT1 can be calculated as shown in Equation (16).

  The drain discharge amount in the first drain trap DT1 can be calculated as in Expression (17).

  Regarding the second drain trap DT2 and subsequent ones, the heat radiation amount of the steam pipe from the n-1 drain trap to the nth drain trap can be calculated as in Expression (18).

  Also, the drain amount before the nth trap can be calculated as in equation (19).

  The drain discharge amount of the nth drain trap can be calculated as shown in Equation (20).

  Thus, the calculated value (calculated drain amount) of the drain flow rate (discharge amount) in the first drain trap DT1 can be calculated from the equation (17), and the second and subsequent drain traps can be calculated from the equation (20). The calculated value (calculated drain amount) of the drain flow rate (discharge amount) in DTn can be calculated.

  Here, the calculated value of the drain flow rate assumes the assumed wetness assuming the wetness of the steam entering the steam pipe 10 (wetness = 1−dryness) and the predetermined thermal characteristics of the steam pipe 10 related to the heat radiation amount. By using the assumed thermal characteristics and the assumed trapping rate assuming the proportion of drain trapped in the drain trap, it can be obtained. In this example, the thermal conductivity λ (heat insulation performance) of the steam pipe is used as the predetermined thermal characteristic related to the heat radiation amount.

  It can be considered that the difference between the calculated drain amount value and the measured drain amount value is the smallest in the optimum value of the combination of the assumed wetness, the assumed thermal characteristic, and the assumed capture rate. In this example, the assumed wetness, the assumed thermal characteristic, and the assumed capture rate are common among the drain traps DT1, DT2, DT3,... DTn. It is possible to estimate the heat dissipation loss of the steam pipe 10 by searching for a combination of the assumed wetness, the assumed heat dissipation loss, and the assumed capture rate so that the difference between the calculated drain amount and the measured drain amount is reduced as a whole. it can.

  FIG. 6 is a flowchart showing a processing procedure regarding heat loss evaluation in this example.

  In FIG. 6, first, initial values (such as the length of each section) relating to the system including the steam pipe 10 and assumed values relating to the wetness, the predetermined thermal characteristics, and the capture rate are input to the calculation device 50 (step 201). 202, and 203). The assumed value that is input first may be empirical reference data or random data.

  In a predetermined section SCn of the steam pipe 10, the sensor PSn measures the temperature (or pressure) in the steam pipe 10. Further, in the drain unit DUn, the temperature sensor 70 and the weight meter 80 measure the total amount of drain discharged from the drain trap DTn and the drain temperature. The calculation device 50 can calculate a calculated value (calculated drain amount) of the drain flow rate in the drain trap DTn using the input initial value, assumed value, measurement data, and the like (step 204).

  Further, the calculation device 50 can calculate the measured value (measured drain amount) of the drain flow rate in the drain trap DTn using the input initial value, measurement data, and the like (step 205).

  From the measured drain amount data and the plurality of calculated drain amount data, the calculation device 50 can perform the optimum state evaluation (step 206). For example, the value of another drain flow rate (calculated drain amount) can be calculated by inputting the shifted assumed value. A plurality of calculated drain amounts are calculated for the drain trap DTn based on the plurality of assumed values. The calculation device 50 compares the calculated drain amount and the measured drain amount with respect to the drain traps DT1, DT2, DT3,... DTn, and assumes that the difference between them (for example, the total deviation) is minimized as a whole. Search for the optimal combination of wetness, assumed thermal properties, and assumed capture rate. For example, the optimal combination can be searched using a statistical method. By such optimal state evaluation, the heat dissipation loss of the steam pipe 10 can be estimated.

  Here, the drain trapping rate is considered to depend on the flow rate of steam in the pipe and the wetness (or dryness) of the steam. Therefore, based on the fluid analysis, the result of the optimum state evaluation can be verified. For fluid analysis, for example, CFD (Computational Fluid Dynamics) can be used.

  The fluid analysis result can be reflected in the optimum state evaluation. An example of the reflection method is shown below.

  In advance, a theoretical formula for the flow rate dependence of the drain capture rate as shown in formula (21) is prepared.

  Specifically, based on the fluid analysis, for example, distribution functions such as Expression (22) and Expression (23) can be determined.

  Next, the deviation between the theoretical formula and the actually measured value is calculated as in formula (24). When there are n measurement values, averaging is performed.

  Considering δtheory, n, the total deviation δ can be calculated as shown in Equation (25).

  By reflecting the fluid analysis result on the result of the optimum state evaluation, the heat dissipation loss of the steam pipe 10 can be estimated more accurately. That is, based on the calculation result of the total deviation or the individual deviation, the result of the optimum state evaluation can be verified. For example, if the overall deviation exceeds a predetermined value, a reanalysis regarding the heat loss of the steam pipe can be performed. If the individual deviation exceeds a predetermined value, the corresponding individual data can be excluded and reanalysis can be performed.

(Example)
Based on the above method, the heat dissipation loss of the steam pipe connected to the boiler was estimated.

The parameter was set to the following range.
(1) Wetness at boiler outlet: 0.1-0.5%
(2) Thermal insulation performance: thermal conductivity 0.01-0.1 W / m / K (thickness 100 mm: measured value),
(3) Drain trap capture rate: 50 to 100%.

  It is known that the thermal conductivity of thermal insulation is about 0.03 to 0.05 W / m / K. However, when calculating the actual heat dissipation amount, factors such as the outside air temperature, wind speed, and deterioration of the thermal insulation were taken into account. .

Each parameter was changed as follows (250 patterns).
(1) Wetness: 5 patterns in increments of 0.1%
(2) Insulation performance: thermal conductivity 10 patterns in increments of 0.01 W / m / K,
(3) Capture rate: 5 patterns in 10% increments.

The following optimal combinations were obtained by the optimal state evaluation.
(1) Wetness: 0.5%
(2) Thermal insulation performance: thermal conductivity 0.03 W / m / K (thickness 100mm),
(3) Capture rate: 40%.

  Table 1 shows calculated values (calculated drain amounts) and measured values (measured drain amounts) of the drain discharge amount in the three drain traps.

  In addition, the fluid dependence of the drain capture rate was analyzed by CFD. As a result, the flow rate dependence of the drain capture rate in the optimum combination showed the same tendency as in the analysis result.

  The numerical value used in the above description is an example, and the present invention is not limited to this.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. The numerical value used in the above description is an example, and the present invention is not limited to this. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. The present invention is not limited by the above description, but only by the appended claims.

It is the schematic which shows a heat loss evaluation system. It is a schematic diagram which shows the mode in the steam pipe before and behind a drain trap. It is the schematic which shows a drain unit. It is a schematic diagram which shows a control unit. It is a flowchart which shows an example of the process sequence regarding heat loss evaluation. It is a flowchart which shows another example of the process sequence regarding heat loss evaluation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat loss evaluation system, 10 ... Steam pipe, 20 ... Steam generation apparatus, 30 ... Load equipment, 40 ... Control unit, 50 ... Calculation apparatus, 60 ... Drain line, 62 ... Temporary hose, 70 ... Temperature sensor (2nd Measuring device), 64 ... receiving tank, 80 ... weighing scale (second measuring device), 123 ... converter, 124 ... CPU, 125 ... memory, 127 ... input device, 128 ... display device, DT1, DT2, DT3,. ..DTn: Drain trap, DU1, DU2, DU3, ... DUn ... Drain unit, SC1, SC2, SC3, ... SCn ... Section, PS1, PS2, PS3, ... PSn ... Sensor (first measurement) apparatus).

Claims (2)

A system for evaluating heat loss in a steam pipe,
A plurality of sections set in a steam pipe through which steam flows;
A first measuring device for measuring at least one of pressure and temperature in the steam pipe;
A plurality of drain units each capable of discharging drain from the end points of the plurality of sections, each of the plurality of drain units each having a drain trap;
A second measuring device for measuring a drain amount value and a drain temperature with each of the plurality of drain units;
Using a measurement result of the first measurement device and a measurement result of the second measurement device, and a calculation device for evaluating a heat dissipation loss of the steam pipe ,
The computing device, heat loss evaluation system of the steam pipe using the assumption capture ratio assuming a ratio of drain, characterized that you evaluate the heat radiation loss of the steam pipe to be trapped in the drain trap. A method for evaluating heat loss in a steam pipe,
A first measuring step for measuring at least one of pressure and temperature in a steam pipe through which steam flows;
A second measurement step of measuring a value related to the amount of drain via the drain trap and a drain temperature for a plurality of sections set in the steam pipe provided with a drain trap at each end point;
Using the measurement result of the first measurement step and the measurement result of the second measurement step, a calculation step for evaluating the heat dissipation loss of the steam pipe,
Inputting an assumed capture rate assuming the percentage of drain trapped in the drain trap;
A method for evaluating heat loss of a steam pipe, comprising:

Images