JP5696526B2 - Steam consumption measuring device - Google Patents

Description

  The present invention relates to a steam usage measuring device that measures the amount of steam that is supplied to a load device from a steam supply source and used in the load device.

There are load devices such as a heating device and a hot air dryer that use steam supplied from a boiler (steam supply source).
The flow rate of steam supplied from a boiler to a load device, that is, the amount of steam used in the load device is measured (see Patent Document 1).
In this case, the steam flow rate is measured using a commercially available steam flow meter interposed in a steam supply line that supplies steam from the boiler to the load device.

JP-A-3-36404

However, the commercially available steam flow meter selects the measurement flow range in accordance with the maximum amount of steam used in the load equipment, and the measurement range has a lower limit. Is difficult to measure accurately. Therefore, there is a problem that the amount of steam used in the load device cannot be accurately grasped.
By the way, the amount of drain generated from the load device when the load device uses the steam supplied from the steam supply source corresponds to the amount of steam used in the load device. Since the drain flow rate can be measured relatively accurately, it is conceivable to measure the amount of steam used based on the drain flow rate.
This invention is made | formed in view of the above points, and it aims at providing the vapor | steam usage measuring device which can measure the usage-amount of the vapor | steam in a load apparatus correctly over a wide range.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a steam usage measuring device for measuring a usage amount of steam supplied to a load device from a steam supply source and used in the load device, A drain flow rate measuring unit that measures a flow rate of drain generated from the load device by using the steam supplied from a steam supply source, and the steam from the drain flow rate measured by the drain flow rate measuring unit. And a steam use amount calculating means for calculating the amount of use.

  According to the first aspect of the present invention, the load device uses the steam supplied from the steam supply source to measure the flow rate of the drain generated from the load device, and is used in the load device from the measured drain flow rate. The amount of steam used was calculated. Therefore, the amount of steam used can be accurately measured over a wide range.

  According to a second aspect of the present invention, the drain flow rate measuring means is interposed in a drain line through which the drain generated from the load device flows, and among the drain line, A flow rate control means interposed at a location downstream of the drain storage section; a differential pressure detection means for detecting a differential pressure between the upstream side and the downstream side of the flow rate control means of the drain line; and the drain storage. Drain flow rate calculation for calculating a drain flow rate per unit time based on the differential pressure detected by the differential pressure detection means in a state where the drain stored in the section flows through the drain line through the flow rate control means And a drain flow rate integrated value calculating unit that calculates an integrated value of the drain flow rate by integrating the drain flow rate calculated by the drain flow rate calculating unit. Is, the steam used amount calculating means, and calculates the integrated value of the amount of steam from the integrated value of the drain flow.

  According to the second aspect of the present invention, the integrated value of the drain flow rate is calculated from the drain flow rate per unit time calculated based on the differential pressure detected by the differential pressure detecting means, and the amount of steam used is calculated from the integrated value. The integrated value of was calculated. Therefore, the integrated value of the amount of steam used can be accurately measured with a simple configuration such as providing the differential pressure detection means, and the configuration can be simplified and the cost can be reduced.

  According to a third aspect of the present invention, the drain flow rate measuring means is interposed in a drain line through which the drain generated from the load device flows, and a drain storage unit that temporarily stores the drain, A time detecting means for detecting an arrival time required until a predetermined fixed amount of drain is accumulated, and a drain flow rate calculating means for calculating a drain flow rate per unit time by dividing the constant amount by the arrival time. The steam usage calculation means calculates the steam usage per unit time from the drain flow rate per unit time.

  According to the invention of claim 3, the arrival time required until a certain amount of drain is stored in the drain tank is detected, and the drain flow rate per unit time is calculated by dividing the certain amount by the arrival time. The amount of steam used per unit time was calculated from the drain flow rate per hour. Therefore, the amount of steam used can be accurately measured with a simple configuration, and the configuration can be simplified and the cost can be reduced.

  According to a fourth aspect of the present invention, the drain flow rate measuring means is configured so that the drain liquid level in the drain reservoir reaches a predetermined low liquid level and is higher than the low liquid level in advance. A liquid level detecting means for detecting that a predetermined high liquid level has been reached, wherein the time detecting means is configured to change the drain liquid level from the low liquid level based on the detection result of the liquid level detecting means; The time required to reach a high liquid level is detected as the arrival time.

  According to the fourth aspect of the present invention, the time required for the drain liquid level to reach the high liquid level from the low liquid level is detected as the arrival time based on the detection result of the liquid level detecting means. Therefore, since the arrival time can be detected with a simple configuration in which the liquid level detection means is provided, the configuration can be simplified and the cost can be reduced.

  According to a fifth aspect of the present invention, the drain flow rate measuring means includes a drain discharge valve provided at a location downstream of the drain reservoir in the drain line, and a detection result of the liquid level detecting means. The drain discharge valve is closed when it is determined that the liquid level of the drain is lower than the low liquid level, and the drain is determined when the liquid level of the drain has reached the high liquid level. Detecting the unit process time as the unit process time when the valve control means for opening the discharge valve and a series of processes in which the drain discharge valve continues closed and then continues open A unit process time detecting means for calculating a drain flow rate per unit process by multiplying the unit process time and the calculated drain flow rate, and each time the unit process is repeated, the unit process time is calculated. Drain flow integrated value calculating means for calculating an integrated value of the drain flow rate by integrating the drain flow rate, wherein the steam usage calculating means is an integrated value of the steam usage from the integrated value of the drain flow rate. Is calculated.

  According to the invention described in claim 5, the drain flow rate per unit process is calculated by multiplying the unit process time and the calculated drain flow rate, and the drain flow rate per unit process is repeated every time the unit process is repeated. Is integrated to calculate the integrated value of the drain flow rate, and the integrated value of the amount of steam used is calculated from the integrated value of the drain flow rate. Therefore, the integrated value of the steam usage can be accurately measured.

  According to the present invention, the flow rate of the drain generated from the load device is measured, and the steam usage amount used in the load device is calculated from the measured drain flow rate. It can be measured.

It is a block diagram which shows the structure of the steam usage measuring apparatus 30 in 1st Embodiment. It is a block diagram which shows the structure of the steam usage-amount measuring apparatus 30 in 2nd Embodiment. It is a flowchart explaining operation | movement of the steam usage measuring device 30 in 2nd Embodiment. (A) thru | or (D) are operation | movement explanatory drawings of the steam usage measuring device 30 in 2nd Embodiment.

(First embodiment)
Hereinafter, an embodiment of a steam usage measuring device according to the present invention will be described with reference to FIG.
In the present embodiment, the case where the steam usage measuring device 30 measures the flow rate of the drain generated from the hot air dryer 10 as the load device will be described.
First, the hot air dryer 10 will be described.
The hot air dryer 10 includes a duct 12, a heat exchanger 14, a drying chamber 16, a steam supply line 18, a drain line 20, a temperature sensor 22, and a load device control unit 24. .

The duct 12 includes, for example, a cylindrical side wall 1202, an upstream side opening 1204 formed at one end in the longitudinal direction of the side wall 1202, and a downstream side opening 1206 formed at the other end.
The heat exchanger 14 is disposed inside the duct 12 and exchanges heat between the steam supplied via the steam supply line 18 and the air A flowing inside the duct 12, thereby It is for heating.
By supplying air A from the blower (not shown) to the upstream opening 1204, the air A flowing inside the duct 12 is heated by the heat exchanger 14, and the heated air is heated from the downstream opening 1206 with hot air Ah. To the drying chamber 16.
The drying chamber 16 stores a dried product, and the dried product is dried by the supplied hot air Ah flowing through the drying chamber 16.

The steam supply line 18 supplies steam supplied from a boiler 26 as a steam supply source to the heat exchanger 14.
The steam supply line 18 is provided with a pressure reducing valve 28 and a control valve 29.
The pressure reducing valve 28 keeps the pressure (back pressure) of the downstream steam constant.
The control valve 29 is disposed on the downstream side of the pressure reducing valve 28 and controls the steam flow rate of the steam supply line 18 by adjusting the opening degree based on the control signal supplied from the load device control unit 24. .

The temperature sensor 22 detects the temperature of the hot air Ah passing through the downstream opening 1206 and supplies the detection result to the load device control unit 24.
The load device control unit 24 gives a control signal to the control valve 29 to control the opening degree so that the temperature of the hot air detected by the temperature sensor 22 is maintained at a predetermined target temperature.

  The drain line 20 collects the drain generated by the steam passing through the heat exchanger 14 at the drain collecting source or discharges the drain. The drain collected in the drain collection source via the drain line 20 is reused as water supply for the boiler 26, for example.

Next, the steam usage measuring device 30 will be described.
The steam usage measuring device 30 includes a drain flow rate measuring means 32 and a steam usage calculating means 34.
The drain flow rate measuring means 32 measures the flow rate of the drain generated from the hot air dryer 10 by using the steam supplied from the boiler 26 by the hot air dryer 10.
The steam usage calculation means 34 calculates the steam usage used in the hot air dryer 10 from the drain flow rate measured by the drain flow rate measurement means 32.

  The drain flow rate measuring means 32 includes a tank 36 as a drain storage part, a drain discharge valve 38, a differential pressure detector 40, a temperature sensor 44, a pressure sensor 46, first and second liquid level sensors 48, 50 and the control part 52 are comprised.

  The tank 36 is interposed in the drain line 20 and temporarily stores the drain, and stores the drain in a state where pressure is applied to the drain. In the drawing, reference numeral 42 indicates an on-off valve provided at the lower portion of the tank 36. The on-off valve 42 is normally closed, and is opened when all the drain stored in the tank 36 is discharged for the purpose of initial drain discharge or maintenance work.

The drain discharge valve 38 is interposed in the drain line 20 at a location downstream of the tank 36 and is controlled to be opened and closed by a control signal supplied from the control unit 52. The drain discharge valve 38 The flow rate control means for controlling the flow rate of the drain is configured.
In the present embodiment, the drain discharge valve 38 is configured by a motor valve or a proportional valve whose opening is adjusted by a control signal.

  The differential pressure detector 40 detects a differential pressure between the upstream side and the downstream side of the drain discharge valve 38 of the drain line 20 and supplies the detection result to the control unit 52, and constitutes a differential pressure detecting means. .

The temperature sensor 44 detects the temperature of the drain stored in the tank 36 and supplies the detection result to the control unit 52.
The pressure sensor 46 detects the pressure of the drain stored in the tank 36 and supplies the detection result to the control unit 52.

The first liquid level sensor 48 detects whether or not the drain liquid level in the tank 36 has reached a predetermined low liquid level L, and supplies the detection result to the control unit 52.
The second liquid level sensor 50 detects whether or not a predetermined high liquid level H higher than the low liquid level L has been reached, and supplies the detection result to the control unit 52.
As the first and second liquid level sensors 48 and 50, a float type liquid level sensor that detects the liquid level based on the position of a float having a specific gravity lighter than that of the drain, or whether the electrode is immersed in the drain Various conventionally known liquid level sensors, such as a capacitance type liquid level sensor that detects the capacitance that changes depending on whether or not, can be used.

In addition, the code | symbol 41 in a figure shows the heat exchanger for subcools interposed between the tank 36, the drain discharge valve 38, and the differential pressure detector 40. FIG.
The heat exchanger 41 for subcooling is provided for the purpose of preventing flash (re-evaporation) by lowering the temperature of the drain flowing from the tank 36 to the drain line 20 by supplying cooling water.
The flush is a phenomenon in which part of the high-temperature drain becomes steam because the pressure on the downstream side of the drain discharge valve 38 is lower than that on the upstream side with respect to the drain discharge valve 38. If the flash occurs, the flow measurement cannot be performed accurately, and the piping may vibrate and adversely affect the durability of the piping.

The control unit 52 is constituted by a microcomputer including a CPU, a ROM, a RAM, an interface and the like connected via a bus line. The ROM stores a control program executed by the CPU, and the RAM provides a working area.
The control unit 52 receives the detection results from the differential pressure detector 40, the temperature sensor 44, the pressure sensor 46, and the first and second liquid level sensors 48 and 50 when the CPU executes a control program, A control signal is supplied to the discharge valve 38 to perform opening / closing control.
Further, the control unit 52 realizes the steam use amount calculating unit 34, the drain flow rate calculating unit 52A, and the drain flow rate integrated value calculating unit 52B, when the CPU executes a control program.

The drain flow rate calculation means 52A is configured to provide a drain per unit time based on the differential pressure detected by the differential pressure detector 40 in a state where the drain stored in the tank 36 flows through the drain line 20 through the drain discharge valve 38. Calculate the flow rate.
Since the drain flow rate is calculated based on the channel cross-sectional area and the differential pressure, the control unit 52 needs to specify the channel cross-sectional area.
In the present embodiment, since the opening degree of the drain discharge valve 38 can be adjusted, the control unit 52 detects the opening degree of the drain discharge valve 38 and specifies a channel cross-sectional area from the opening degree. The flow path cross-sectional area is specified based on the map from the detected opening.

The drain flow rate integrated value calculation unit 52B calculates the integrated value of the drain flow rate by integrating the drain flow rate calculated by the drain flow rate calculation unit 52A.
More specifically, the drain flow rate integrated value calculation means 52B measures the time during which the drain discharge valve 38 is open (the time during which the drain passes through the drain discharge valve 38), and the time and unit time. By multiplying the permeate drain flow rate, an integrated value of the drain flow rate that flows while the drain discharge valve 38 is open is calculated.

Next, the operation of the steam usage measuring device 30 will be described.
Drain generated from the hot air dryer 10 by operating the hot air dryer 10 using steam supplied from the boiler 26 is stored in the tank 36 via the drain line 20.
If the drain liquid level increases as the amount of drain stored in the tank 36 increases, and eventually the second liquid level sensor 50 detects that the drain liquid level has reached the high liquid level H. The drain discharge valve 38 is controlled from the closed state to the open state.
As a result, the drain stored in the tank 36 is supplied to the drain recovery source through the drain discharge valve 38.

By supplying the drain from the tank 36 to the drain recovery source, the drain liquid level drops as the amount of drain stored in the tank 36 decreases, and eventually the liquid level becomes lower than the low liquid level L. The liquid level of the drain is not detected by the first liquid level sensor 48.
Then, the control unit 52 controls the drain discharge valve 38 from the open state to the closed state, and again stores the drain in the tank 36.

During a period in which the drain stored in the tank 36 flows through the drain line 20 through the drain discharge valve 38, the drain flow rate calculation means 52 </ b> A performs drain per unit time based on the differential pressure detected by the differential pressure detector 40. Calculate the flow rate.
Further, the drain flow rate integrated value calculation means 52B multiplies the drain flow rate per unit time calculated by the drain flow rate calculation means 52A by the open time of the drain discharge valve 38 at that time, and integrates the multiplied value. The integrated value of the drain flow rate is calculated by calculating the integrated value of the flow rate, or integrating the integrated value by integrating the change value of the drain flow rate per unit time with respect to time.

The steam usage calculation means 34 calculates an integrated value of the steam usage from the integrated value of the drain flow calculated by the drain flow integration value calculation means 52B.
The calculated integrated value of the steam usage is supplied to, for example, an external device such as a personal computer (not shown), displayed on a display device of the external device, or stored in a storage medium of the external device.

The drain discharge valve 38 may be an electromagnetic valve that can be switched between fully open and fully closed. In this case, the drain flow rate calculation means 52A is configured to have a flow path cross-sectional area when the drain discharge valve 38 is fully open. The drain flow rate may be calculated based on the differential pressure. In this case, the solenoid valve constitutes the flow rate control means.
In addition to the drain discharge valve 38, an orifice is provided in the drain line 20, the differential pressure between the upstream side and the downstream side of the orifice is detected by the differential pressure detector 40, and the drain flow rate calculation means 52A detects the detected differential pressure. The drain flow rate may be calculated based on the flow path cross-sectional area of the orifice. In this case, the orifice constitutes the flow rate control means.

As explained above, according to the first embodiment, the hot air dryer 10 uses the steam supplied from the boiler 26 to measure the flow rate of the drain generated from the hot air dryer 10 and measure the drain. The amount of steam used in the hot air dryer 10 is calculated from the flow rate of the air.
In other words, the flow rate of the liquid phase drain can be accurately measured compared to the steam flow rate, so that the steam consumption can be measured over a wide range compared to when measuring the steam flow rate with a commercially available steam flow meter. Accurate measurement is possible.
Therefore, even when the load device is a low load, the amount of steam used can be accurately measured.

In the present embodiment, the differential pressure detector 40 detects the differential pressure between the upstream side and the downstream side of the drain discharge valve 38, and the drain flow rate is calculated from the drain flow rate per unit time calculated based on the differential pressure. The integrated value of the steam consumption was calculated from the integrated value.
Therefore, the integrated value of the amount of steam used can be accurately measured with a simple configuration such as providing the differential pressure detection means, and the configuration can be simplified and the cost can be reduced.

(Second Embodiment)
Next, a second embodiment will be described.
FIG. 2 is a configuration diagram showing the configuration of the steam usage measuring device 30 in the second embodiment.
In the following embodiments, the same or the same parts and members as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted or the description will be simplified.
As shown in FIG. 2, the steam usage measuring device 30 includes a drain flow rate measuring means 32 and a steam usage calculating means 34 as in the first embodiment, but the configuration of the drain flow measuring means 32. Is different from the first embodiment.
As shown in FIG. 2, the drain flow rate measuring means 32 includes a tank 36, a drain discharge valve 38, a time detection means 54A, a drain flow rate calculation means 54B, a valve control means 54C, and a unit process time detection means 54D. The drain flow rate integrated value calculating means 54E is included.
Note that the steam usage calculation means 34, time detection means 54A, drain flow rate calculation means 54B, valve control means 54C, unit process time detection means 54D, and drain flow rate integrated value calculation means 54E are controlled by the CPU of the control unit 52. It is realized by executing.

Similar to the first embodiment, the tank 36 is interposed in the drain line 20 and temporarily stores the drain.
As in the first embodiment, the drain discharge valve 38 is interposed in the drain line 20 at a location downstream of the tank 36 and is controlled to be opened and closed by a control signal supplied from the control unit 52. The

The time detection means 54A detects the arrival time required until a predetermined amount of drain is stored in the tank 36.
Specifically, the control unit 52 detects the arrival time using a timer that performs a time measuring operation. The controller 52 starts the timer to measure the time, and the controller 52 resets the timer to initialize the timer.
In the second embodiment, the certain amount of drain is the amount of drain required for the drain liquid level in the tank 36 to reach the high liquid level H from the low liquid level L.
The time detecting means 54A reaches the high liquid level H by the second liquid level sensor 50 after the first liquid level sensor 48 detects that the drain liquid level has reached the low liquid level L. The time required until this is detected is detected as the arrival time.
Therefore, in the second embodiment, the first and second liquid level sensors 48 and 50 indicate that the drain liquid level in the tank 36 has reached the predetermined low liquid level L and the low level is low. A liquid level detecting means for detecting that a predetermined high liquid level H higher than the liquid level L has been reached is configured.

  The drain flow rate calculation means 54B calculates the drain flow rate per unit time by dividing the fixed amount by the arrival time.

  The valve control unit 54C closes the drain discharge valve 38 when it is determined that the drain liquid level is lower than the low liquid level L based on the detection results of the first and second liquid level sensors 48 and 50. When it is determined that the liquid level of the drain has reached the high liquid level H, the drain discharge valve 38 is opened.

The unit process time detection means 54D detects the time required for a unit process as a unit process time when a series of processes in which the drain discharge valve 38 continues to be closed and then continues to open is defined as a unit process.
Specifically, the control unit 52 detects the unit process time using the timer.

  The drain flow rate integrated value calculation means 54E calculates the drain flow rate per unit process by multiplying the unit process time and the calculated drain flow rate, and integrates the drain flow rate per unit process every time the unit process is repeated. By doing so, the integrated value of the drain flow rate is calculated.

  The steam usage calculation means 34 calculates the steam usage per unit time from the drain flow rate per unit time calculated by the drain flow rate calculation means 54B, and calculates the drain flow rate calculated by the drain flow rate integrated value calculation means 54E. Calculate the integrated value of the amount of steam used from the integrated value.

Next, operation | movement of the steam usage measuring device 30 is demonstrated with reference to the flowchart of FIG. 3, and operation | movement explanatory drawing of FIG.
When the operation of the hot air dryer 10 is started, first, the control unit 52 opens the drain discharge valve 38 and discharges the drain in the tank 36 prior to the start of the measurement operation so that the liquid level of the drain is low. If the position L is reached, the drain discharge valve 38 is closed (step S10). And the control part 52 starts a timer (step S12).
As shown in FIGS. 4A and 4B, along with the operation of the hot air dryer 10, drain is supplied to the tank 36 through the drain line 20, and the liquid level of the drain in the tank 36 gradually increases.

The control unit 52 determines whether or not the drain liquid level has reached the high liquid level H based on the detection result of the second liquid level sensor 50 (step S14).
If the determination result in step S14 is No, the control unit 52 repeats step S14.
As shown in FIG. 4 (C), if the drain liquid level reaches the high liquid level H and the determination result in step S14 is Yes, the controller 52 discharges the drain as shown in FIG. 4 (D). The valve 38 is changed from the closed state to the open state, and the drain is discharged from the tank 36 (step S16: valve control means 54C). And the control part 52 detects arrival time based on the timing result of a timer (step S18: time detection means 54A).
And the control part 52 calculates the drain flow rate per unit time by dividing | segmenting the said fixed amount by arrival time (step S20: drain flow rate calculation means 54B).
Then, the control unit 52 calculates the steam usage per unit time from the drain flow rate per unit time (step S22: steam usage calculation means 34).

The drain liquid level in the tank 36 gradually falls. The control unit 52 determines whether or not the drain liquid level has reached the low liquid level L based on the detection result of the first liquid level sensor 48 (step S24).
If the determination result of step S24 is No, the control unit 52 repeats step S24.
As shown in FIG. 4E, if the drain liquid level reaches the low liquid level L and the determination result in step S24 is Yes, the drain discharge valve 38 is changed from the open state to the closed state (step S26: valve). Control means 54C).
And the control part 52 detects unit process time based on the time-measurement result of a timer (step S28: unit process time detection means 54D). Here, the unit process time corresponds to a time required when a series of processes (steps S12 to S26) in which the drain discharge valve 38 continues to be closed and then opened is set as a unit process.
Next, after resetting and initializing the timer, the control unit 52 starts up and starts the clocking operation again (step S30).

The control unit 52 calculates the drain flow rate per unit process by multiplying the unit process time detected in step S28 by the drain flow rate per unit time calculated in step S20, and the drain per unit process. By integrating the flow rate, an integrated value of the drain flow rate is calculated (steps S32, S34: drain flow rate integrated value calculating means 54E).
And the control part 52 calculates the integrated value of steam usage from the integrated value of drain flow (step S36: Steam usage calculation means 34).
Next, the control unit 52 proceeds to step S14 and repeats the processing loop of steps S14 to S36. Therefore, every time this processing loop is executed (each time the unit process is repeated), step S34 is executed, whereby the drain flow rate per unit process is integrated.
Further, the steam usage per unit time calculated in steps S22 and S36, and the integrated value of the steam usage are supplied to an external device such as a personal computer (not shown) and displayed on the display device of the external device, for example. Alternatively, it is stored in a storage medium of an external device.
In the present embodiment, in the unit process, the period in which the drain discharge valve 38 is kept open and the drain is discharged, and the period in which the drain discharge valve 38 is kept closed In both cases, it is assumed that the flow rate of the drain flowing into the tank 36 is substantially the same.

As described above, according to the second embodiment, similarly to the first embodiment, the flow rate of the drain generated from the hot air dryer 10 is measured, and the hot air dryer 10 is determined from the measured drain flow rate. The amount of steam used in was calculated.
Therefore, even when the load device has a low load, the amount of steam used can be accurately measured over a wide range.

Further, in the second embodiment, the arrival time required until a predetermined amount of drain is stored in the tank 36 is detected, and the drain flow rate per unit time is calculated by dividing the certain amount by the arrival time. The amount of steam used per unit time is calculated from the drain flow rate per unit time.
Therefore, compared with the case where the flow rate of steam is measured with a commercially available steam flow meter, the amount of steam used can be accurately measured over a wide range.
Further, as compared with the first embodiment, the differential pressure detector 40 for detecting the differential pressure between the upstream side and the downstream side of the drain discharge valve 38 is not required, so that the configuration is simplified and the cost is reduced. Can be planned.

Further, in the second embodiment, the time required for the drain liquid level to reach the high liquid level H from the low liquid level L based on the detection results of the first and second liquid level sensors 48 and 50 is determined. Detected as arrival time.
Therefore, since the arrival time can be detected by a simple configuration in which the first and second liquid level sensors 48 and 50 are provided in the tank 36, the configuration can be simplified and the cost can be reduced.

Further, in the second embodiment, when a series of processes in which the drain discharge valve 38 continues to be closed and then continues to be opened is defined as a unit process, the time required for the unit process is detected as a unit process time. Calculate the drain flow rate per unit process by multiplying the process time and the calculated drain flow rate, and calculate the integrated value of the drain flow rate by integrating the drain flow rate per unit process every time the unit process is repeated. Then, the integrated value of the amount of steam used is calculated from the integrated value of the drain flow rate.
Therefore, the integrated value of the steam usage can be accurately measured based on the drain flow rate per unit time.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG.
In the third embodiment, a drain flow rate is detected by inserting a commercially available flow meter (drain flow meter) in the drain line 20.
The location where the flow meter is interposed is not limited as long as it is a location on the drain line 20 shown in FIG.
Specifically, it may be any one of a location X between the load device and the tank 36, a location Y between the tank 36 and the drain discharge valve 38, and a location Z downstream of the drain discharge valve 38.
However, in order to accurately detect the flow rate of the drain, from the viewpoint that it is preferable that the pressure change received by the drain is small, a pressure change is likely to occur when the drain discharge valve 38 changes from the closed state to the open state. Location X and location Y with less pressure change are more preferable than location Z.

In the third embodiment, the flow rate of the drain generated from the load device may be detected by a flow meter as follows, and the amount of steam used may be calculated based on the detected flow rate of the drain.
That is, when the flow meter is interposed at the location X, the control unit 52 detects the drain supplied from the load device to the tank 36 via the drain line 20 with the flow meter, and detects the detected drain. The integrated value of the amount of steam used may be calculated and the integrated value of the amount of steam used may be calculated from the integrated value of the flow rate.
When the flow meter is provided at the location Y and location Z, the control unit 52 is discharged from the tank 36 via the drain line 20 when the drain discharge valve 38 is opened. The drain may be detected by a flow meter, an integrated value of the detected drain flow rate may be calculated, and an integrated value of the steam usage may be calculated from the integrated value of the flow rate.
In the third embodiment as well, the amount of steam used can be accurately measured as in the first embodiment.

DESCRIPTION OF SYMBOLS 10 ... Hot air dryer 20 ... Drain line 26 ... Boiler 30 ... Steam usage measuring device 32 ... Drain flow rate measuring means 34 ... Steam usage calculating means 36 ... Tank 38 ... Drain discharge valve 40 ... ... Differential pressure detector 44 ... Temperature sensor 46 ... Pressure sensor 48 ... First liquid level sensor 50 ... Second liquid level sensor 52 ... Control unit 52A ... Drain flow rate calculating means 52B ... Drain flow rate Integrated value calculating means 54A... Time detecting means 54B ... Drain flow rate calculating means 54C ... Valve control means 54D ... Unit process time detecting means 54E ... Drain flow rate integrated value calculating means

Claims (2)

A steam usage measuring device that measures the amount of steam that is supplied from a steam supply source to a load device and used in the load device,
A drain flow rate measuring means for measuring a flow rate of drain generated from the load device by using the steam supplied from the steam supply source by the load device;
And a steam usage amount calculation means for calculating the amount of the steam from the flow rate of drain measured by said drain flow measuring means,
The drain flow rate measuring means is
A drain storage section that is interposed in a drain line through which drain generated from the load device flows, and temporarily stores the drain;
Of the drain line, a drain discharge valve that is interposed at a location downstream of the drain storage part and can be adjusted in opening degree;
Differential pressure detecting means for detecting a differential pressure between the upstream side and the downstream side of the drain discharge valve of the drain line;
Corresponding to the differential pressure detected by the differential pressure detection means and the opening of the drain discharge valve in a state where the drain stored in the drain storage part flows through the drain line through the drain discharge valve A drain flow rate calculating means for calculating a drain flow rate per unit time based on the flow path cross-sectional area;
Drain flow integrated value calculating means for calculating the integrated value of the drain flow by integrating the drain flow calculated by the drain flow calculating means,
The steam usage measuring device is characterized in that the steam usage calculating means calculates an integrated value of the steam usage from the integrated value of the drain flow rate. The drain flow rate measuring means further comprises means for detecting the opening degree of the drain discharge valve, and a map for identifying the flow path cross-sectional area at the opening degree from the opening degree of the drain discharge valve,
The steam usage measuring device according to claim 1, wherein the drain flow rate calculation unit specifies a flow path cross-sectional area based on the map from the detected opening of the drain discharge valve.

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