JP5492282B1 - Heat exchanger operation device - Google Patents

Abstract

A heat exchanger operating device capable of indicating an accurate maintenance time without being affected by scale adhesion to a transmitter.
In the heat exchanger operating device according to the present invention, the secondary fluid pressure difference at the inlet / outlet of the heat exchanger and the secondary fluid flow rate of the heat exchanger are measured (step S31), the secondary fluid differential pressure and 2 A secondary side flow rate coefficient is calculated based on the secondary fluid flow rate (step S32), and a secondary flow path contamination coefficient is calculated based on the secondary side flow rate coefficient (step S33). The maintenance time is notified based on the secondary channel contamination coefficient calculated by the coefficient calculation means (steps S34 to S36).
[Selection] Figure 3

Description

  The present invention relates to a heat exchanger operating device, and more particularly to a heat exchanger operating device capable of indicating an accurate maintenance time of a heat exchanger.

  In the hot spring method, “hot water at a spring outlet is 25 ° C or higher and contains a predetermined amount of a predetermined component” (Onsen Law Article 2) is recognized as a hot spring. Often used.

  And as a heating apparatus for spring water, it is common to use the plate-type heat exchanger which uses hot water as a primary fluid and spring water as a secondary fluid.

  However, when the heat exchanger is operated for a long period of time, components contained in the spring water become scales and adhere to the plate, so that the overall heat transfer coefficient decreases, and the spring water may not be heated sufficiently.

  In order to avoid such a state, it is necessary to disassemble and clean the heat exchanger. However, as a guideline for determining the cleaning time, an apparatus for monitoring and estimating the contamination coefficient has already been proposed (for example, Patent Document 1). See 3).

  Patent Document 1 uses a device that monitors the fouling coefficient of the heat exchanger itself, and Patent Document 2 and Patent Document 3 use a device for evaluating the fouling coefficient of the heat exchanger body using an evaluation device installed in the bypass channel. Disclosure.

Japanese Unexamined Patent Publication No. 2000-333657 (FIG. 1) JP 07-146263 A (paragraph [0010], FIG. 1) JP 2010-90782 A (paragraph [0023], FIG. 1)

  However, all of the conventional contamination coefficient monitoring / estimating devices are required to measure the flow rate of the primary fluid and the heat exchanger inlet / outlet temperature and the flow rate of the secondary fluid and the heat exchanger inlet / outlet temperature. Therefore, it is difficult to avoid the scale from adhering to the measuring device, particularly the secondary fluid temperature measuring transmitter at the outlet of the heat exchanger, and there is a problem that the temperature measurement value itself is not reliable and an accurate maintenance time cannot be grasped.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat exchanger operating device capable of indicating an accurate maintenance time without being affected by scale adhesion to the transmitter.

  The “heat exchanger” used in this specification means a plate heat exchanger unless otherwise specified.

The heat exchanger operating device according to the present invention comprises a secondary fluid differential pressure measuring means for measuring a secondary fluid differential pressure that is a difference between a secondary fluid pressure at the heat exchanger inlet and a secondary fluid pressure at the heat exchanger outlet; A secondary fluid flow rate measuring means for measuring the secondary fluid flow rate of the heat exchanger, and a secondary side flow channel for calculating a secondary side flow rate coefficient based on the secondary fluid differential pressure and the secondary fluid flow rate 2 calculated by a flow coefficient calculating means, a secondary flow dirt coefficient calculating means for calculating a secondary flow dirt coefficient based on the secondary flow rate coefficient, and a secondary flow dirt coefficient calculating means. Maintenance time notification means for notifying the maintenance time based on the secondary channel contamination coefficient, heat exchanger inlet primary fluid pressure measurement means for measuring the primary fluid pressure at the heat exchanger inlet, and primary at the heat exchanger outlet Heat exchanger outlet primary fluid pressure measuring means for measuring fluid pressure, and heat exchange Heat exchanger inlet secondary fluid pressure measuring means for measuring the secondary fluid pressure at the inlet of the heat exchanger, heat exchanger outlet secondary fluid pressure measuring means for measuring the secondary fluid pressure at the heat exchanger outlet, and the heat exchanger The primary value which is the average value of the primary fluid pressure measured by the inlet primary fluid pressure measuring means and the primary fluid pressure measured by the heat exchanger outlet primary fluid pressure measuring means. Primary fluid average pressure calculating means for calculating fluid average pressure, heat exchanger inlet secondary fluid pressure measured by the heat exchanger inlet secondary fluid pressure measuring means, and heat exchanger outlet secondary fluid pressure measuring means The secondary fluid average pressure calculating means for calculating the secondary fluid average pressure which is the average value of the secondary fluid pressure measured at the heat exchanger, and the primary fluid average calculated by the primary fluid average pressure calculating means Pressure and secondary fluid average pressure calculator Comprising a secondary flow coefficient correcting means for correcting the secondary passage flow coefficient in based on the calculated secondary fluid average pressure, a.

With the above configuration, it is possible to indicate an accurate maintenance time without being affected by scale adhesion. Furthermore, it becomes possible to determine the maintenance time accurately.

  The heat exchanger operating device according to the present invention measures an expected overall heat transfer coefficient calculating means for calculating an expected overall heat transfer coefficient based on the secondary channel fouling coefficient, and measures the secondary fluid temperature at the heat exchanger inlet. Heat exchanger inlet secondary fluid temperature measuring means, heat exchanger inlet primary fluid temperature measuring means for measuring the primary fluid temperature at the heat exchanger inlet, and primary fluid for measuring the primary fluid flow rate of the heat exchanger Based on the flow rate measuring means, the predicted overall heat transfer coefficient, the heat exchanger inlet secondary fluid temperature, the heat exchanger inlet primary fluid temperature and the primary fluid flow rate, the predicted heat exchanger outlet secondary fluid temperature is determined. And a predicted heat exchanger outlet secondary fluid temperature calculating means for calculating.

  With the above configuration, the heat exchanger outlet secondary fluid temperature can be predicted with high accuracy.

  A heat exchanger operating device according to the present invention includes a heat exchanger outlet secondary fluid temperature measuring means for measuring a secondary fluid temperature at a heat exchanger outlet, and a heat exchanger for measuring a primary fluid temperature at a heat exchanger outlet. Based on the outlet primary fluid temperature measuring means, the heat exchanger inlet primary fluid temperature, the heat exchanger outlet primary fluid temperature, the heat exchanger inlet secondary fluid temperature, and the heat exchanger outlet secondary fluid temperature. A result integrated heat transfer coefficient calculating means for calculating a result integrated heat transfer coefficient, and the difference between the actual control heat transfer coefficient and the expected control heat transfer coefficient is greater than a predetermined threshold value. And a coefficient learning means for learning the coefficient of the secondary flow path dirt coefficient calculation means in response.

  With the above configuration, the maintenance time can be determined more accurately.

  The heat exchanger operating device according to the present invention includes the heat exchanger outlet primary fluid temperature, the heat exchanger inlet primary fluid temperature, the heat exchanger outlet secondary fluid temperature, and the heat exchanger inlet secondary fluid temperature. And a temperature measuring means maintenance time notifying means for notifying the maintenance time of the heat exchanger outlet secondary fluid temperature measuring means.

  With the above-described configuration, it becomes possible to indicate the maintenance time of the heat exchanger outlet secondary fluid temperature transmitter to which the scale easily adheres.

  According to the heat exchanger operation device according to the present invention, it is possible to notify the maintenance time of the heat exchanger with almost no influence of scale adhesion.

It is a flow sheet of the hot spring bath facility where the heat exchanger operation device according to the present invention is applied. It is a block diagram which shows the hardware constitutions of the heat exchanger operating device which concerns on this invention. It is a flowchart of a heat exchanger maintenance time alerting routine. It is a flowchart of a predicted heat exchanger outlet secondary fluid temperature calculation routine. It is a flowchart of a learning main routine. It is a flowchart of a learning subroutine. It is a flowchart of a flow coefficient correction routine. It is a flowchart of a temperature transmitter maintenance time notification routine.

  FIG. 1 is a flow sheet of a hot spring bathing facility to which a heat exchanger operating device according to the present invention is applied, including a boiler 11, a primary fluid circulation pump 12, a heat exchanger 13, a secondary fluid transfer pump 14, and It is composed of bathtubs 15, 16 and 17. In addition, the fuel of the boiler 11 is not prescribed | regulated in particular, City gas, heavy oil, etc. may be sufficient. Further, the number of bathtubs is not particularly specified.

  The secondary fluid (hot spring water) that springs from the source well 18 is supplied to the secondary flow path of the heat exchanger 13 by the secondary fluid transfer pump 14.

  The secondary fluid heated by the heat exchanger 13 is supplied to the three bathtubs 15, 16 and 17 via the three flow control valves 191, 192 and 193.

  The three bathtubs 15, 16 and 17 are assumed to be poured, and the treatment system for overflowing hot spring water is not shown.

  The primary side of the heat exchanger 13 is filled with a primary fluid that is heat transfer water, and is heated by the boiler 11. The primary fluid is circulated by a primary fluid circulation pump 12 driven by a variable speed motor.

  The heat exchanger operating device according to the present invention is used to accurately determine the maintenance time for removing the scale attached to the secondary flow path of the heat exchanger 13.

  FIG. 2 is a block diagram showing the hardware configuration of the heat exchanger operating apparatus according to the present invention, and includes a computer system 2, a transmitter 3 for measuring the state of a hot spring bath facility, and a periphery for exchanging information with an operator. It is comprised from the apparatus 4.

  That is, the computer system 2 includes a CPU 21, a memory 22, a hard disk (HD) 23, a process interface 24 and a peripheral interface 25 with a bus 20 as a center.

  The transmitter 3 measures the fluid flow rate, fluid temperature, fluid pressure, etc. of the hot spring bath facility and supplies data to the computer system 2 via the process interface 24.

  The peripheral device 4 includes, for example, a display 41, a keyboard 42, and a mouse 43, and exchanges information with the computer system 2 through the peripheral interface 25.

Note that the peripheral device 4 may be configured with an operation panel that has been generally used conventionally.
Hereinafter, a structure, an effect | action, and an effect are demonstrated for every Example.

[First Embodiment]
Since the primary fluid uses a fluid containing almost no scale, such as tap water, in the closed loop flow path, the adhesion of the scale to the primary flow path of the heat exchanger 13 can be ignored.

  On the other hand, since the secondary fluid uses the hot spring water that springs from the source well 18 as it is, the components contained in the hot spring water adhere to the secondary flow path of the heat exchanger 13 as the scale passes over time. In addition, the flow area of the secondary fluid is reduced and the flow resistance of the secondary flow path is increased.

  Therefore, in the heat exchanger operating device according to the present invention, the maintenance time is estimated from the change over time of the flow coefficient representing the flow characteristics of the secondary side flow path.

That is, in the first embodiment, the secondary fluid flow rate F ₂ is measured between the secondary fluid transfer pump 14 and the heat exchanger secondary fluid inlet in order to calculate the flow coefficient of the secondary side flow path. In order to measure the pressure loss ΔP ₂ when the secondary fluid flows through the secondary flow path of the heat exchanger 13, the differential pressure transmitter 312 is provided in the secondary flow path of the heat exchanger. Install.

  As the secondary fluid flow rate transmitter 311, it is desirable to use an electromagnetic type with little risk of scale adhesion.

  FIG. 3 is a flowchart of a heat exchanger maintenance time notification routine executed by the computer system 2, and is executed at regular time intervals (for example, every minute).

First, the computer system 2 reads the secondary fluid flow rate F ₂ and the secondary pressure loss ΔP ₂ (step S31).

Next, the computer system 2 calculates the flow coefficient A _v of the heat exchanger secondary side flow path using Equation 1 (step S32).

Next, the computer system 2 calculates the expected contamination coefficient r _f of the heat exchanger secondary side flow path (step S33).

In calculating the expected contamination coefficient r _f , the following conditions 1 to 4 are assumed.

  Condition 1: In the plate heat exchanger, the width (D) between the partition plates is extremely small compared to the horizontal length and the vertical length of the partition plates, and the scale is proportional to the operation time x. It is assumed that it adheres to the next side surface with a uniform thickness (= d / 2), and [Equation 2] holds.

Condition 2: The flow coefficient _Av is proportional to the channel width (= D−d) through which the secondary fluid actually flows, and [Equation 3] holds.

Condition 3: The expected dirt coefficient r _f of the partition plate is proportional to the thickness of the scale (= d / 2), and [Equation 4] is established.

It [Number 2] no [Expression 5] [Equation 4] obtained, the computer system 2 calculates the predicted fouling coefficient r _f using Equation 5.

Next, the computer system 2 calculates the time average value r _fav of the expected dirt coefficient r _f in order to prevent erroneous determination due to the temporary fluctuation of the dirt coefficient (step S34).

Then, the computer system 2 determines whether or not the time average predicted contamination coefficient r _fav is _{equal to} or greater than a predetermined threshold value r _fth (step S35).

When the computer system 2 determines in step S35 that the time average expected dirt coefficient r _fav is _{equal to} or greater than a predetermined threshold value r _fth (YES), a message stating that “maintenance time has come” is displayed on the display 42. It is displayed (step S36).

On the other hand, when the computer system 2 determines in step S35 that the time-average predicted contamination coefficient r _fav is not _{equal to} or greater than the predetermined threshold value r _fth (NO), the computer system 2 ends this routine without displaying a message. To do.

  As described above, according to the first embodiment, the maintenance time of the heat exchanger is based on the measurement results of the secondary fluid flow rate transmitter 311 and the secondary side flow rate differential pressure transmitter 312 that hardly cause scale adhesion. Can be accurately notified.

  Furthermore, by operating only the secondary side of the heat exchanger, that is, without operating the boiler 11 and the primary circulation pump 12, the maintenance time of the heat exchanger can be known, which is advantageous from the viewpoint of energy saving. It is.

[Second Embodiment]
In the hot spring bath facility to which the heat exchanger operation apparatus according to the present invention is applied, it is important to accurately control the temperature of the secondary fluid supplied to the bathtubs 15 to 17, that is, the hot water supply temperature.

  However, the secondary outlet on the heat exchanger is the place where the scale is most likely to adhere, and high-precision measurement cannot be expected even if a temperature transmitter is installed.

Therefore, in the heat exchanger operating device according to the present invention, a heat exchanger simulator is configured in the computer system 2 to calculate the predicted heat exchanger outlet secondary fluid temperature t _2e , and this value is used to determine the hot water supply temperature. I have control.

In order to configure the heat exchanger simulator, in the second embodiment, a heat exchanger inlet secondary fluid temperature transmitter 321 that measures the secondary fluid temperature T _2i at the heat exchanger inlet, and the heat exchanger primary side A heat exchanger inlet primary fluid temperature transmitter 322 for measuring the inlet primary fluid temperature T _1i and a primary fluid flow transmitter 323 for measuring the primary fluid flow rate F ₁ are additionally provided.

  The secondary fluid has a relatively low temperature on the inlet side of the heat exchanger, and there is little scale deposition, and it is possible to maintain the accuracy of temperature measurement over a long period of time.

  FIG. 4 is a flowchart of a predicted heat exchanger outlet secondary fluid temperature calculation routine executed by the computer system 2 and is executed subsequent to the heat exchanger maintenance time notification routine.

First, the computer system 2 reads the heat exchanger inlet secondary fluid temperature T _2i , the heat exchanger inlet primary fluid temperature T _1i, and the primary fluid flow rate F ₁ (step S41).

Next, the computer system 2 calculates the predicted overall heat transfer coefficient u as a function value of the primary fluid flow rate F ₁ , the primary fluid flow rate F ₂ and the predicted soil coefficient r _f by [Equation 6] (step S 42).

The computer system 2 then calculates the heat exchanger inlet primary fluid temperature T _1i , the heat exchanger inlet secondary fluid temperature T _2i , the primary fluid flow rate F ₁ , the primary fluid flow rate F _2, and the expected overall heat transfer coefficient u. The expected heat exchanger outlet secondary fluid temperature _t2e , which is a function value, is calculated by [ _Equation 7] (step S43).

By performing feedback control using the rotation speed of the primary fluid circulation pump as an operation end so that the predicted heat exchanger outlet secondary fluid temperature t _2e becomes a target temperature (for example, 41 degrees Celsius), the bathtubs 15 to 17 It becomes possible to control the temperature of the secondary fluid supplied to the desired temperature.

  As described above, according to the second embodiment, the heat exchanger inlet secondary fluid temperature transmitter 321, the heat exchanger inlet primary fluid temperature transmitter 322, and the primary fluid flow transmitter 323 are less likely to cause scale adhesion. As a result, it is possible to estimate the secondary fluid temperature at the outlet of the heat exchanger without adding a secondary fluid outlet temperature transmitter to which the scale easily adheres.

[Third Embodiment]
In the heat exchanger operating apparatus according to the present invention, dirt coefficients from the flow coefficient A _v of the secondary-side flow path using Equation 5, further expected overall heat transfer coefficient by using the number 6] Although u is calculated, the constant of [Equation 5] should be determined based on the actual driving performance.

  However, if it is determined based on the operation results, a contradiction arises that the heat exchanger operation device according to the present invention cannot be operated at least until the first maintenance time.

  Therefore, in the heat exchanger operating device according to the present invention, a learning function for learning preset constants during operation is added.

In order to realize the learning function, in the third embodiment, the heat exchanger outlet secondary fluid temperature transmitter 331 that measures the secondary fluid temperature T _2e at the heat exchanger outlet, and the primary fluid at the heat exchanger body outlet are measured. A heat exchanger outlet primary fluid temperature transmitter 332 for measuring the temperature T _1e is additionally provided.

  FIG. 5 is a flowchart of a learning main routine executed by the computer system 2 and is executed subsequent to the predicted secondary fluid temperature calculation routine.

First, the computer system 2 reads the heat exchanger outlet secondary fluid temperature _T2e and the heat exchanger outlet primary fluid temperature _T1e (step S51).

Next, the computer system 2 calculates a primary temperature difference ΔT ₁ which is a difference between the heat exchanger inlet primary fluid temperature T _1i and the heat exchanger outlet primary fluid temperature T _1e (step S52), and then heat. A secondary temperature difference ΔT ₂ which is a difference between the exchanger outlet secondary fluid temperature T _2e and the heat exchanger inlet secondary fluid temperature T _2i is calculated (step S53).

Next, the computer system 2 calculates the logarithmic average temperature difference ΔT using [Equation 8] from the primary temperature difference ΔT ₁ and the secondary temperature difference ΔT ₂ (step S54).

Next, the computer system 2 calculates the actual result heat transfer coefficient U using [Equation 9] from the logarithm average temperature difference ΔT and the secondary fluid flow rate F ₂ (step S55).

Next, the computer system 2 determines whether the absolute value of the difference between the expected overall heat transfer coefficient u and the actual overall heat transfer coefficient U is larger than a predetermined deviation epsilon _U (step S56).

When the computer system 2 determines that the absolute value of the difference between the predicted overall heat transfer coefficient u and the actual overall heat transfer coefficient U is greater than or equal to the deviation ε _U (YES), the computer system 2 uses [Equation 10] to obtain the actual dirt coefficient. _Rf is calculated (step S57).

Then, in accordance with the deviation between the expected fouling coefficient _{r f} and actual dirt coefficient _{R f} (2-4) to learn the constant of equation (step S58).

When the computer system 2 determines that the absolute value of the difference between the imaginary overall heat transfer coefficient u and the actual overall heat transfer coefficient U is not greater than or equal to the deviation ε _U (NO), the computer system 2 directly ends this routine.

  The learning method in step S58 is not particularly defined, but the following learning method can be applied as an example.

  FIG. 6 is a flowchart of a learning subroutine executed by the computer system 2.

The computer system 2 reads out the flow coefficient _AV and the actual dirt coefficient _Rf stored in the hard disk 23 every predetermined period (for example, one week) (step S61).

Next, the computer system 2 obtains BSL (Best Straight Line) by the least square method using the flow coefficient _AV as an independent variable and the actual dirt coefficient _Rf as a dependent variable (step S62).

  Then, the computer system 2 determines whether or not there is data deviating from a predetermined range (for example, ± 2σ) centered on BSL in the data read from the hard disk 23 (step S63).

  When the computer system 2 determines that there is data deviating from the predetermined range (YES), the computer system 2 deletes the data (step S64), returns to step S62, and obtains BSL again.

When the computer system 2 determines that there is no data deviating from the predetermined range (NO), the coefficient K _r1 in [Equation 5] is replaced with the BSL Y-intercept (step S65), and K _r2 is the slope of the BSL. (Step S66), and this routine is finished.

  As described above, according to the third embodiment, the contamination coefficient is calculated from the flow coefficient by additionally installing the heat exchanger outlet secondary fluid temperature transmitter 331 and the heat exchanger primary fluid outlet temperature transmitter 332. The coefficient of the linear function equation to be corrected can be corrected based on the operation results, and the maintenance time can be accurately determined.

[Fourth Embodiment]
The heat exchanger used in the heat exchanger operation apparatus according to the present invention is a plate type, and the partition plate that partitions the primary flow path and the secondary flow path is as thin as about 0.5 to 1 millimeter, so that the primary fluid or The partition plate may be deformed by the change in the pressure of the secondary fluid, and the calculation accuracy of the flow coefficient of the secondary flow path may be deteriorated.

  For example, when the pressure of the primary fluid is high, the primary flow path width is widened and the secondary flow path width is narrowed.

  Therefore, the heat exchanger operating device according to the present invention is provided with a flow coefficient correction means for correcting the flow coefficient according to the difference between the primary flow path average pressure and the secondary flow path average pressure.

In order to realize the flow coefficient correction means, the heat exchanger inlet primary fluid pressure transmitter 341 that measures the primary fluid pressure P _1i at the heat exchanger inlet, the heat that measures the primary fluid pressure P _1e at the heat exchanger outlet. Exchanger outlet primary fluid pressure transmitter 342, heat exchanger inlet secondary fluid pressure transmitter 343 that measures secondary fluid pressure P _2i at the heat exchanger inlet, and secondary fluid pressure P _2e at the heat exchanger outlet is measured. A heat exchanger outlet secondary fluid pressure transmitter 344 is additionally installed.

  FIG. 7 is a flowchart of a flow coefficient correction routine executed by the computer system 2 and is executed following the learning routine.

The computer system 2 starts with a heat exchanger inlet primary fluid pressure P _1i , a heat exchanger outlet primary fluid pressure P _1e , a heat exchanger inlet secondary fluid pressure P _2i , and a heat exchanger outlet secondary fluid pressure P. _2e is read (step S71).

Next, the computer system 2 calculates a heat exchanger primary fluid average pressure P _1M that is an average value of the heat exchanger inlet primary fluid pressure P _1i and the heat exchanger outlet primary fluid pressure P _1e (step S72). Then, a heat exchanger secondary fluid average pressure P _2M that is an average value of the heat exchanger inlet secondary fluid pressure P _2i and the heat exchanger outlet secondary fluid pressure P _2e is calculated (step S73).

Next, the computer system 2 calculates a flow coefficient correction coefficient C _v that is a function value of the heat exchanger primary fluid average pressure P _1M and the heat exchanger secondary fluid average pressure P _2M based on [Equation 11]. (Step S74).

Finally, the flow coefficient A _v calculated in [Equation 1] is multiplied by the flow coefficient correction coefficient C _v to calculate a corrected flow coefficient A _vc (step S75), and this routine is terminated.

As described above, according to the fourth embodiment, the heat exchanger inlet primary fluid pressure transmitter 341, the heat exchanger outlet primary fluid pressure transmitter 342, the heat exchanger inlet secondary fluid pressure transmitter 343, and the heat by additionally provided an exchanger outlet secondary fluid pressure transmitter 344, to correct the error of the flow coefficient a _v due to deformation of the partition plate of the heat exchanger 13, to more accurately determine the maintenance timing of the heat exchanger It becomes possible.

[Fifth Embodiment]
In the third embodiment, a heat exchanger outlet secondary fluid temperature transmitter 331 for measuring the secondary fluid temperature T _2e at the heat exchanger outlet is additionally provided, but the detection of the heat exchanger outlet secondary fluid temperature transmitter 331 is performed. Since it is necessary to insert the end into the high-temperature secondary fluid, the scale easily adheres and it is difficult to maintain detection accuracy.

  Therefore, the heat exchanger operating device according to the present invention is provided with a maintenance time notification means for the heat exchanger outlet secondary fluid temperature transmitter 331.

  It is not necessary to add a new transmitter in order to realize the maintenance time notification means.

  FIG. 8 is a flowchart of a temperature transmitter maintenance time notification routine executed by the computer system 2 and is executed subsequent to the flow coefficient correction routine.

First, the computer system 2 includes a heat exchanger inlet primary fluid temperature T _1i , a heat exchanger outlet primary fluid temperature T _1e , a heat exchanger inlet secondary fluid temperature T _2i , and a heat exchanger outlet secondary fluid temperature T _2e. The primary fluid flow rate F ₁ and the secondary fluid flow rate F ₂ are read (step S81).

Next, the computer system 2 calculates the primary side exchange heat quantity by [Equation 12] based on the heat exchanger inlet primary fluid temperature T _1i , the heat exchanger outlet primary fluid temperature T _1e , and the primary fluid flow rate F _1. to calculate the Q ₁ (step S82).

Next, the computer system 2 calculates the secondary side exchange heat quantity by [Equation 13] based on the heat exchanger inlet secondary fluid temperature T _2i , the heat exchanger outlet secondary fluid temperature T _2e , and the secondary fluid flow rate F _2. to calculate the Q ₂ (step S83).

In the present embodiment, it can be considered heat loss of the plate type heat exchanger is very small because the primary heat exchanger duty Q ₁ and the secondary heat exchanger duty Q ₂ is substantially equal to, the threshold epsilon _T a predetermined When a large difference occurs, it can be considered that the detection accuracy of the heat exchanger outlet secondary fluid temperature transmitter 331 is deteriorated due to the scale adhesion.

Therefore, the computer system 2, the difference between the inlet heat exchanger duty Q ₁ and the secondary heat exchange rate Q ₂ it is determined whether larger than the threshold value epsilon _T (step S84), and larger than the threshold value ε _T (YES) If determined, the heat exchanger outlet secondary fluid temperature transmitter 331 is notified that maintenance is necessary (step S85), and this routine is terminated.

On the other hand, if it is determined that greater than the threshold value ε _T (NO) is immediately terminated routine.

  As described above, according to the fifth embodiment, it is possible to notify the maintenance time of the heat exchanger outlet secondary fluid temperature transmitter 331 without newly installing a transmitter.

  The heat exchanger operating device according to the present invention can accurately notify the maintenance time of the heat exchanger without being affected by scale adhesion to the transmitter, and is industrially useful.

2 Computer system 3 Transmitter 4 Peripheral device 11 Boiler 12 Primary fluid circulation pump 13 Heat exchanger 14 Secondary fluid transfer pump 15, 16, 17 Bath 18 Source well 20 Bus 21 CPU
22 memory 23 hard disk 24 process interface 25 peripheral interface 41 display 42 keyboard 43 mouse 191, 192, 193 flow control valve 311 secondary fluid flow transmitter 312 differential pressure transmitter 321 heat exchanger inlet secondary fluid temperature transmitter 322 heat exchanger inlet 1 Secondary fluid temperature transmitter 323 Primary fluid flow transmitter 331 Heat exchanger outlet secondary fluid temperature transmitter 332 Heat exchanger outlet primary fluid temperature transmitter 341 Heat exchanger inlet primary fluid pressure transmitter 342 Heat exchanger outlet primary fluid pressure transmitter 343 Heat exchanger inlet secondary fluid pressure transmitter 344 Heat exchanger outlet secondary fluid pressure transmitter

Claims (4)

Secondary fluid differential pressure measuring means for measuring a secondary fluid differential pressure, which is a difference between the secondary fluid pressure at the heat exchanger inlet and the secondary fluid pressure at the heat exchanger outlet;
Secondary fluid flow rate measuring means for measuring the secondary fluid flow rate of the heat exchanger;
Secondary side flow rate coefficient calculating means for calculating a secondary side flow rate coefficient based on the secondary fluid differential pressure and the secondary fluid flow rate;
Secondary channel contamination coefficient calculating means for calculating a secondary channel contamination coefficient based on the secondary channel flow rate coefficient;
Maintenance time notification means for notifying the maintenance time based on the secondary flow path contamination coefficient calculated by the secondary flow path contamination coefficient calculation means;
Heat exchanger inlet primary fluid pressure measuring means for measuring the primary fluid pressure at the heat exchanger inlet;
Heat exchanger outlet primary fluid pressure measuring means for measuring the primary fluid pressure at the heat exchanger outlet;
Heat exchanger inlet secondary fluid pressure measuring means for measuring the secondary fluid pressure at the heat exchanger inlet;
Heat exchanger outlet secondary fluid pressure measuring means for measuring the secondary fluid pressure at the heat exchanger outlet;
The average value of the heat exchanger inlet primary fluid pressure measured by the heat exchanger inlet primary fluid pressure measuring means and the heat exchanger outlet primary fluid pressure measured by the heat exchanger outlet primary fluid pressure measuring means. Primary fluid average pressure calculating means for calculating a primary fluid average pressure which is:
The average value of the heat exchanger inlet secondary fluid pressure measured by the heat exchanger inlet secondary fluid pressure measuring means and the heat exchanger outlet secondary fluid pressure measured by the heat exchanger outlet secondary fluid pressure measuring means. Secondary fluid average pressure calculating means for calculating a secondary fluid average pressure which is:
The secondary side flow rate coefficient is corrected based on the primary fluid average pressure calculated by the primary fluid average pressure calculating means and the secondary fluid average pressure calculated by the secondary fluid average pressure calculating means. A heat exchanger operating device comprising secondary side flow coefficient correction means . An expected overall heat transfer coefficient calculating means for calculating an expected overall heat transfer coefficient based on the secondary channel contamination coefficient;
Heat exchanger inlet secondary fluid temperature measuring means for measuring the secondary fluid temperature at the heat exchanger inlet;
Heat exchanger inlet primary fluid temperature measuring means for measuring the primary fluid temperature at the heat exchanger inlet;
Primary fluid flow rate measuring means for measuring the primary fluid flow rate of the heat exchanger;
Expected heat exchange for calculating the predicted heat exchanger outlet secondary fluid temperature based on the predicted overall heat transfer coefficient, the heat exchanger inlet secondary fluid temperature, the heat exchanger inlet primary fluid temperature, and the primary fluid flow rate. The heat exchanger operating device according to claim 1, further comprising: an outlet secondary fluid temperature calculating means. Heat exchanger outlet secondary fluid temperature measuring means for measuring the secondary fluid temperature at the heat exchanger outlet;
Heat exchanger outlet primary fluid temperature measuring means for measuring the primary fluid temperature at the heat exchanger outlet;
Based on the heat exchanger inlet primary fluid temperature, the heat exchanger outlet primary fluid temperature, the heat exchanger inlet secondary fluid temperature, and the heat exchanger outlet secondary fluid temperature, an actual performance heat transfer coefficient is calculated. Results management heat transfer coefficient calculation means,
When the absolute value of the difference between the actual overall heat transfer coefficient and the expected overall heat transfer coefficient is larger than a predetermined threshold, the coefficient of the secondary flow path contamination coefficient calculating means is learned according to the difference. The heat exchanger operating device according to claim 2, further comprising coefficient learning means. Based on the heat exchanger outlet primary fluid temperature, the heat exchanger inlet primary fluid temperature, the heat exchanger outlet secondary fluid temperature, and the heat exchanger inlet secondary fluid temperature, the heat exchanger outlet secondary fluid The heat exchanger operating device according to claim 3 , further comprising: a temperature measuring means maintenance time notifying means for notifying a maintenance time of the fluid temperature measuring means .

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