JP2012072992A - Water supply control device and boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water supply control device capable of accurately detecting deterioration in a water supply pump on supplying water to a water pipe of a boiler by proportional control by continuously driving the water supply pump, and to provide a boiler using the water supply control device.SOLUTION: The water supply control device proportionally controls a water supply amount of a water supply unit on the basis of a predetermined parameter in a boiler which includes a water pipe, a heating unit for heating water in the water pipe, and the water supply unit for continuously supplying water to the water pipe. A water supply control unit (water supply control device) of the boiler includes a means of detecting deterioration of a water supply pump, the means outputting a signal upon detecting a deteriorated state of the water supply pump when the control amount on the water supply unit exceeds a prescribed range.

Description

  The present invention relates to a water supply control device that supplies water to a water pipe of a boiler including a heating unit such as a burner by proportional control, and a boiler labo using the water supply control device.

  For example, as a water supply system for supplying water to equipment such as a boiler, based on an intermittent control system that repeats “ON-OFF” of a water supply pump to supply a predetermined amount of water, and various parameters such as combustion amount and line pressure Techniques relating to a proportional control method in which an output frequency of an inverter is calculated and water is continuously supplied by a water supply pump are disclosed (for example, see Patent Documents 1 and 2).

JP 2010-0708204 A JP 2008-188540 A

In the intermittent control method, for example, when a predetermined amount of water is supplied, the water supply pump is driven at a constant output such as a rated output, and therefore, by measuring the “ON time” in the intermittent operation of the water supply pump. It is possible to detect deterioration of the feed pump.
However, when the feed water pump is continuously driven and water is supplied by proportional control, the feed water pump is always driven, so that it is not easy to detect deterioration of the feed water pump.
Therefore, there is a technical request to accurately detect deterioration of the water supply pump in a proportional control method in which the water supply pump is continuously driven and supplied with proportional control.

  The present invention has been made in consideration of such circumstances. When the feed water pump is continuously driven and water is supplied to the water pipe of the boiler by proportional control, it is possible to accurately detect deterioration of the feed water pump. An object is to provide a possible water supply control apparatus and a boiler using the water supply control apparatus.

In order to solve the above problems, the present invention proposes the following means.
Invention of Claim 1 is a boiler provided with the water pipe, the heating part which heats the water in this water pipe, and the water supply part which supplies water to the said water pipe continuously, The water supply amount of the said water supply part is set. A water supply control device that performs proportional control based on a preset parameter, and the water supply control unit outputs a signal when a deterioration state of the water supply pump is detected when a control amount for the water supply unit exceeds a predetermined range. And a feed water pump deterioration detecting means.

According to the water supply control device according to the present invention, when water is supplied by proportional control by continuously driving a water supply pump to the water pipe of the boiler, the water supply unit is configured to supply a predetermined amount of water corresponding to a preset parameter. A control amount is detected, and the deterioration of the feed water pump is detected when the control amount exceeds a predetermined range.
As a result, it is possible to detect the deterioration of the feed water pump, to perform proper maintenance of the feed water pump, and to suppress deterioration and breakage due to overheating of the boiler.

In this specification, when the control amount exceeds the predetermined range, for example, a setting range composed of a lower limit value and an upper limit value (for example, a setting range such as x1 to x2), a lower limit value or more, and a lower limit value exceeded. It is a concept including the state, the upper limit value or less, and the lower limit value.
In addition, various concepts indicating a range such as an offset amount with respect to a reference set value (for example, x3 or more, or less for the set value, or x4% or more for the set value) are included.

According to the water supply control device and the boiler according to the present invention, when the water supply pump is continuously driven to supply water by proportional control, the deterioration of the water supply pump can be detected by detecting the control amount for the water supply unit.
As a result, it is possible to detect the deterioration of the feed water pump, to perform proper maintenance of the feed water pump, and to suppress deterioration and breakage due to overheating of the boiler.

It is a figure showing the schematic structure of the boiler concerning a 1st embodiment of the present invention. It is a flowchart explaining the effect | action of the water supply control apparatus which concerns on 1st Embodiment. It is a flowchart explaining the effect | action of the water supply control apparatus which concerns on 2nd Embodiment of this invention.

The first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a diagram illustrating a schematic configuration of a small once-through boiler 10 according to the first embodiment, and FIG. 2 is a flowchart illustrating the operation of the water supply control device.

  The boiler 10 includes a housing 11, a can body (water pipe) 12, a burner (heating section) 16, a combustion gas discharge pipe 17, a blower 18, a fuel supply section 19, a water supply section 20, and an economizer 30. And a control unit 40. The control unit 40 includes a combustion control unit that controls the combustion amount of the burner 16, and a water supply control unit (water supply control device) that controls the amount of water supplied to the can body 12. is doing.

  The can 12 includes a water tube group 13, a lower header 14 </ b> A located below the water tube group 13, and an upper header 14 </ b> B located above the water tube group 13, and the combustion gas G <b> 2 generated by the burner 16 is generated. In addition, it moves toward the combustion gas discharge pipe 17 through the combustion gas passage formed in the water pipe group 13.

  The upper header 14B is connected to a pressure sensor 7 for detecting the pressure of the steam in the upper header 14B, and a castable (refractory) 11A is provided above the lower header 14A and below the upper header 14B. Is arranged.

  The burner 16 is formed, for example, in a box shape having a nozzle portion 16A on the surface on the water tube group 13 side, and a plurality of nozzle holes are arranged in a planar shape in the nozzle portion 16A and premixed supplied by a blowing means The gas G1 is supplied to the nozzle portion 16A.

Further, the burner 16 can control the combustion state (for example, high combustion, low combustion) based on the pressure of the steam detected by the pressure sensor 7, for example.
In FIG. 1, a broken line portion extending from the nozzle portion 16A to the water tube group 13 side conceptually represents a flame generated by the nozzle portion 16A.

  The premixed gas G1 supplied to the nozzle portion 16A is injected and burned from the nozzle hole to become a high-temperature combustion gas G2, and the combustion gas G2 passes through the combustion gas passage 12G formed in the water tube group 13. Then, the water W in the water tube group 13 is heated and then introduced into the economizer 30 through the discharge path 17A.

  The combustion gas discharge pipe 17 is connected to the end of the combustion gas passage 12G, and constitutes a discharge passage 17A for discharging the combustion gas G2 to the outside of the boiler 10, and the discharge passage 17A guides the combustion gas G2 to the economizer 30. ing.

  The blower means 18 includes a blower 18A, an air supply passage 18B, and a damper 18C. The blower 18A transfers the combustion air A1 to the air supply passage 18B, and the fuel supplied from the combustion air A1 and the fuel supply unit 19 is supplied. The gas G0 is mixed in the supply passage 18B to become the premixed gas G1, and is supplied to the burner 16.

The blower 18A rotates the blower fan to supply the combustion air A1, and the blower 18A in this embodiment controls the number of rotations of the blower fan by an inverter corresponding to the combustion state of the burner 16 and burns it. The blast volume of the working air A1 is adjusted.
Further, the opening degree of the damper 18C can be controlled by a motor (not shown), and the amount of combustion air A1 can be adjusted together with the blower 18A or independently.

  The fuel supply unit 19 includes a fuel supply pipe 19A and a flow rate adjustment valve 19B. By controlling the flow rate adjustment valve 19B, an amount of fuel gas G0 corresponding to the combustion state of the burner 16 is supplied to the fuel supply pipe 19A. It comes to supply.

  The water supply unit 20 includes a water supply line 21 connected to the water supply source S, a water quality measurement unit 22, a water supply pump 23, a flow rate adjustment valve 24, a flow meter 25, and a check valve 26. The water W is supplied to the can body 12 through the economizer 30.

  The economizer 30 uses the waste heat of the combustion gas G2 that has passed through the water tube group 13 to heat the water W supplied to the can 12 to save energy, and heat exchange disposed in the discharge path 17A. Water W is allowed to flow through the section to exchange heat with the combustion gas G2 to heat the water W, and the heated water W is supplied to the lower header 14A of the can body 12.

The control unit 40 is configured to control the amount of combustion of the burner 16 and the amount of water supplied to the can 12, and includes an input unit 41, a memory 42, a calculation unit 43, a hard disk 44, and an output unit 46. The communication unit 47 includes an input unit 41, a memory 42, a calculation unit 43, a hard disk 44, and an output unit 46.
The hard disk 44 stores a first database 45A and a second database 45B.

  The input unit 41 includes, for example, a data input device such as a keyboard (not shown) and can output settings and the like to the calculation unit 43. The pressure sensor 7, the water quality measurement unit 22, the flow meter 25, and the pressure for water supply The sensor 27 and the water temperature sensor 28 are connected to each other by a signal line 48A, and signals input from the pressure sensor 7, the water quality measurement unit 22, the flow meter 25, the water supply pressure sensor 27, and the water temperature sensor 28 are output to the calculation unit 43. It has become.

  The output unit 46 is connected to the blower 18A, the damper 18C, the flow rate adjustment valve 19B, the water supply pump 23, the flow rate adjustment valve 24 and the signal line 48B, and the signal from the calculation unit 43 is sent to the blower 18A, the damper 18C, the flow rate adjustment valve 19B, It outputs to the feed water pump 23 and the flow rate adjustment valve 24.

  The calculation unit 43 reads and executes a program stored in a storage medium (for example, ROM) of the memory 42, calculates a combustion amount of the burner 16 by the combustion control unit based on an input from the input unit 41, The amount of water supplied to the can 12 is calculated by the water supply control unit.

In the first database 45A, for example, numerical data indicating the relationship between the current pressure and the combustion amount for transferring the current pressure to the set pressure is stored in the form of a data table.
The combustion controller refers to the first database 45A from the steam pressure detected by the pressure sensor 7, calculates the combustion amount of the burner 16, the blower 18A, the damper 18C, and the control amount of the flow rate adjusting valve 19B. Control amounts are output to the blower 18A, the damper 18C, and the flow rate adjusting valve 19B, and the burner 16 is controlled to a combustion state corresponding to the combustion amount.

  Further, in the second database 45B, for example, parameters including the combustion amount of the burner 16, the feed water pressure of the feed water line 21, the feed water temperature of the feed water line 21, the blow amount of a blow line (not shown), and the feed water amount by the feed water unit 20 are provided. Numerical data indicating the relationship between the valve opening of the flow rate adjusting valve 24 and the inverter frequency with respect to the water supply pump 23 is stored in the form of a data table.

  The water supply control unit refers to the second database 45B from signals input from the flow meter 25, the water pressure sensor 27, and the water temperature sensor 28 via the input unit 41, and sets parameters (water supply amount, water supply Based on the feed water pressure and feed water temperature of the line 21 and the parameters (combustion amount and blow amount of the burner 16) stored in the memory 42, the valve opening of the flow rate adjusting valve 24 and the output frequency of the inverter to the feed pump 23 ( Control amounts) (hereinafter referred to as inverter frequency) and the like, and these control amounts are output to the output unit 46.

  Further, the water supply control unit compares the amount of water supplied to the can body 12 input from the flow meter 25 with the reference amount of water to be supplied corresponding to the amount of combustion of the burner 16, and the amount of water supplied by the flow meter 25 Is fed back to the inverter frequency for the feed water pump 23 so as to approach the reference water supply amount, and the calculated inverter frequency (set value) is adjusted to an inverter frequency that can correspond to the reference water supply amount. Yes.

  In the first embodiment, the amount of water supplied by the water supply control unit is controlled, for example, by controlling the valve opening degree of the flow rate adjusting valve 24 only in accordance with the combustion state of the burner 16, and using parameters other than the combustion state. The water supply amount control based on this is assumed to be proportionally controlled by the inverter frequency for the water supply pump 23.

  Further, the water supply control unit has a deterioration detection unit (water supply pump deterioration detection means) for detecting deterioration of the water supply pump, and the inverter frequency calculated when obtaining a predetermined water supply amount and a predetermined water supply When the inverter frequency for obtaining a predetermined water supply amount is out of the predetermined range with respect to the set inverter frequency by comparing with the set inverter frequency for obtaining the amount, for example, a signal such as an alarm is output. It has become.

Next, with reference to FIG. 2, the outline of the deterioration detection of the feed water pump 23 by a deterioration detection part is demonstrated.
1) First, the water supply control parameters (for example, the combustion amount of the burner 16, the water supply temperature, the pressure, the blow amount), the inverter frequency for driving the water supply pump 23, and the allowable range of the inverter frequency are set (S1). In addition, as an allowable range of the inverter frequency, for example, an upper limit value of the inverter frequency is set. For example, when the inverter frequency for obtaining a predetermined water supply amount is 40 Hz, when the frequency becomes about 57 Hz or more, the deterioration occurs. A signal related to detection is output. .
2) Next, it is determined whether the boiler 10 is in operation (S2). When the boiler 10 is in operation, the process proceeds to S3, and when it is not in operation, the control is terminated.
3) A water supply control parameter is acquired (S3). If S3 is performed, it will transfer to S4.
4) A set water supply amount is set based on the water supply control parameter (S4).
5) The calculation unit 43 adjusts the inverter frequency for driving the water supply pump 23 based on the set water supply amount (S5).
6) The computing unit 43 calculates the amount of water supply based on the signal input from the flow meter 25 (S6).
7) The computing unit 43 compares the water supply amount detected in S6 with the set water supply amount to determine whether the water supply amount has reached a steady state (S7). If the water supply amount is not in a steady state, the process proceeds to S2, and if the water supply amount is in a steady state, the process proceeds to S8.
8) The calculation unit 43 compares the inverter frequency for driving the feed water pump 23 adjusted in S5 with the frequency allowable value to determine whether the inverter frequency is within the allowable range (S8). If the inverter frequency is within the allowable range, the process proceeds to S2, and if the inverter frequency is outside the allowable range, the process proceeds to S9.
9) An alarm is output (S9).
When S9 is executed, the process proceeds to S2.
While driving, the above 2) to 9) are repeated.

According to the water supply control unit according to the first embodiment, when the water supply amount is controlled based on a preset parameter, for example, the inverter frequency for the water supply pump 23 to ensure a predetermined water supply amount is the set inverter. The deterioration of the feed water pump 23 can be detected by the fact that the inverter frequency is out of the allowable range such that the frequency becomes equal to or higher than the frequency.
As a result, accurate maintenance of the feed water pump 23 can be performed, and as a result, deterioration and breakage due to overheating of the boiler 10 can be suppressed.

Next, a water supply control unit according to the second embodiment of the present invention will be described.
The second embodiment differs from the first embodiment in that, in the first embodiment, the water supply control unit adjusts the flow rate by the water supply unit 20 based on the inverter frequency for the water supply pump 23. On the other hand, in the second embodiment, the water supply control unit controls the flow rate adjustment based on the inverter frequency for the water supply pump 23 and the valve opening degree of the flow rate adjustment valve 24.

  FIG. 3 is a flowchart showing the operation of the deterioration detection unit according to the second embodiment. The setting in S101 is different from the flowchart (FIG. 2) according to the first embodiment. The difference in that the deterioration of the water supply pump 23 can be detected by either the adjustment of the valve opening or the determination regarding the valve opening related to S110, depending on either the inverter frequency for the water supply pump 23 or the valve opening of the flow rate adjustment valve 24. ing.

  As a result, in the second embodiment, the deterioration detection unit detects the deterioration of the feed water pump 23 even if only one of the inverter frequency and the flow rate adjustment valve 24 valve opening degree of the feed water pump 23 is out of the allowable range. it can. Others are the same as those in the first embodiment, and a description thereof is omitted.

According to the water supply control unit according to the second embodiment, since the water supply amount is adjusted by the valve opening degree of the flow rate adjusting valve 24 in addition to the water supply pump 23, the water supply width (maximum water supply amount / minimum water supply amount) is increased. At the same time, water supply accuracy can be improved.
Further, since the deterioration of the water supply pump 23 can be detected when either the water supply pump 23 or the flow rate adjusting valve 24 is out of the allowable range, the reliability can be improved.

  The present invention is not limited to the first and second embodiments, and various modifications can be made without departing from the spirit of the invention.

  Further, the case where the boiler is the small once-through steam boiler 10 has been described. However, in addition to the small once-through type boiler, the heating pipe is directly connected by a multi-tube boiler in which water pipes are arranged in an annular shape, a furnace tube flue boiler, and a burner. You may apply to the boiler of various structures, such as a hot water heater to heat.

  Moreover, in the said embodiment, although the case where the water W was supplied to the can 12 via the economizer 30 was demonstrated, it cannot be overemphasized that it is good also as a structure which is not equipped with the economizer 30. FIG.

In the above embodiment, the case where the water supply control unit adjusts the flow rate using the water supply pump 23 or the flow rate adjustment using the water supply pump 23 and the flow rate adjustment valve 24 is described. However, only the valve opening degree of the flow control valve 24 is described. It is good also as a structure which adjusts water supply amount and controls, and it is also possible to apply to the water supply part which consists of another known structure.
The proportional control based on the inverter frequency with respect to the water supply pump 23 is a simple concept (including a constant amount), PI control, and PID control, which can be arbitrarily set.

  In the first embodiment, the deterioration detection unit detects the inverter frequency for the water supply pump 23. In the second embodiment, the deterioration detection unit detects the inverter frequency for the water supply pump 23 and the flow rate adjustment valve 24. Although the case of detecting the valve opening has been described, the target of the control amount detected and monitored by the deterioration detection unit may be selected from the control amount other than the inverter frequency and the valve opening.

  In the second embodiment, the case where the deterioration detection unit outputs a signal when either the inverter frequency or the valve opening is out of the allowable range has been described. However, both the inverter frequency and the valve opening are out of the allowable range. It is good also as a structure which outputs a signal when it becomes.

  Moreover, although the said embodiment demonstrated the case where the control amount which concerns on the inverter frequency with respect to the water supply pump 23 and the valve opening degree of the flow volume adjustment valve 24 was set based on the water supply amount by the water supply part 20, it was set as water supply amount. Instead, for example, a configuration based on other characteristics such as a water level detected by a water level meter communicating with the water pipe may be used.

Moreover, in the said embodiment, as a parameter at the time of setting the water supply amount of the water supply part 20, combustion amount (blower rotation (inverter frequency)), water supply temperature (water temperature gauge), line pressure (pressure sensor), concentration Although the case where the blow amount (blow valve opening) is used has been described, the parameters relating to the water supply control can be arbitrarily combined.
That is, a control amount related to water supply control may be set based on a part of the parameters, or a part of the parameters may be replaced with another parameter, or a part or all of the parameters and another parameter may be replaced. You may control combining.

  In the above embodiment, the case where an alarm is output when degradation is detected has been described. However, instead of the alarm or together with the alarm, other signals such as a stop signal of the boiler 10 are output. May be.

  According to the water supply control device and the boiler according to the present invention, since the deterioration of the water supply pump can be detected by monitoring the control amount for the water supply unit, it is industrially applicable.

16 Burner (heating unit)
12 Can body (water pipe)
20 Water Supply Unit 23 Water Supply Pump 24 Flow Control Valve 40 Control Unit (Water Supply Control Device, Water Supply Pump Deterioration Detection Means)

Claims (4)

In a boiler provided with a water pipe, a heating part for heating water in the water pipe, and a water supply part for continuously supplying water to the water pipe, the water supply amount of the water supply part is proportional based on a preset parameter A water supply control device for controlling,
The water supply control unit
A water supply control device comprising: a water supply pump deterioration detecting means for outputting a signal when a deterioration state of the water supply pump is detected when a control amount for the water supply unit exceeds a predetermined range. The water supply control device according to claim 1,
The feed water pump deterioration detecting means is
A water supply control device, wherein the deterioration state of the pump is detected by an inverter frequency for driving the pump. The water supply control device according to claim 1,
The water supply unit has a flow rate adjustment valve,
The feed water pump deterioration detecting means is
A water supply control device configured to detect a deterioration state of the pump based on an opening degree of a flow rate adjustment valve when the water supply unit supplies a predetermined amount of water.   A boiler comprising the water supply control device according to any one of claims 1 to 3.

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