JP2001324102A - Boiler apparatus and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the imbalance of the furnace wall temperature of a boiler apparatus. SOLUTION: The boiler apparatus is provided with inlet headers 3 on the inlet sides of a plurality of water pipes extending along a furnace wall 1 of a furnace, outlet headers 5 on the outlet sides of the water pipes, water- supplying means 25, which supply water to the water pipes via branch pipes respectively connected to the water pipes, and a pressure loss control means 35 which control the flow rate of the water by means of variable orifices installed to predetermined branch pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a boiler device,
In particular, the present invention relates to a control means and a control method of a water pipe flow rate for reducing imbalance of furnace wall temperature.

[0002]

2. Description of the Related Art In general, a boiler device has a large number of water tubes extending vertically along a furnace wall forming a furnace as a combustion chamber. When water is supplied from the lower end of the water pipe, the water is heated by the heat of the furnace, and is extracted as high-temperature water or steam from the upper end of the water pipe.

[0003] In such a boiler apparatus, there is a possibility that the temperature of the furnace wall becomes unbalanced, the temperature difference or local overheating may damage the furnace wall or increase the life consumption. For this reason, the diameter of the water pipe is partially changed, or an orifice or the like that restricts the flow rate by pressure loss is provided in the pipe that supplies water to some water pipes, and the flow rate of the water pipe is partially increased or decreased, and The imbalance in furnace wall temperature is reduced by increasing or decreasing the amount of heat transfer to a specific water pipe.

[0004]

However, in the prior art, no consideration is given to a change in the temperature distribution of the furnace wall due to a change in operating conditions such as a heat load. That is, as described above, the elements that determine the flow rate of the water pipe, such as the diameter of the water pipe and the specifications of the orifice, are set in the design stage, assuming a certain example of the operating conditions, so the operating conditions have changed. In this case, there is a possibility that the imbalance in the furnace wall temperature cannot be sufficiently reduced.

[0005] In view of the above problems, an object of the present invention is to reduce imbalance in furnace wall temperature.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a plurality of water pipes extending along a furnace wall of a furnace, and water supply means for supplying water to the water pipes through branch pipes respectively connected to the plurality of water pipes. The above problem is solved by providing a well-known variable flow control means such as a variable orifice in a predetermined branch pipe. With such a configuration, the flow rate supplied to a specific part of the water pipe is controlled by a variable flow rate control means provided in the corresponding branch pipe, and the amount of heat transfer from the furnace wall to the water pipe is increased or decreased. Thus, the temperature of the surrounding furnace wall can be controlled. That is, when the flow rate is increased by operating the flow rate control means, the amount of heat transferred from the furnace wall to the water pipe increases, and the temperature of the surrounding furnace wall decreases. vice versa,
Reducing the flow reduces the amount of heat transfer from the furnace wall to the water pipe,
The surrounding furnace wall temperature rises. According to this, by partially adjusting the furnace wall temperature using the flow control means,
It is possible to reduce the imbalance in the furnace wall temperature due to the change in the operating conditions. Such a variable flow control means is preferably provided for all the branch pipes, but may be provided only for some of the branch pipes as necessary.

Further, it is preferable to provide a temperature measuring means for measuring a temperature of a furnace wall near a water pipe to which water is supplied by the predetermined branch pipe. According to this, the reliability of the control of the furnace wall temperature can be ensured by feeding back the actual furnace wall temperature to the flow control of the water pipe as needed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a boiler apparatus to which the present invention is applied will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of the boiler of the present embodiment. FIG. 2 is an exploded view showing a furnace wall of the boiler device of FIG.

[0009] The boiler device includes a furnace wall 1 constituting a furnace,
An inlet header 3 provided on the inlet side of water tubes extending vertically along the furnace wall 1, an outlet header 5 provided on the outlet side of these water tubes, and a node for supplying water to the inlet header 3 It has a charcoal 7. As shown in FIG. 2, the furnace wall 1 includes a substantially rectangular front wall 9, a rear wall 11, a left side wall 13, and a right side wall 15. And the front wall 9
At the lower part of the rear wall 11, a burner 10 for combustion is arranged facing the furnace, and above the burner 10, an after-air port 12 for supplying air to the furnace is arranged so as to open to the furnace wall. . A large number of water tubes are formed along these furnace walls at substantially equal intervals. A large number of upper water pipes 17 extending substantially in the vertical direction are formed in the upper part of each furnace wall. The spiral water pipe 19 surrounding the furnace in a spiral manner by extending diagonally across the lower part of the furnace wall.
Are formed in the same number in communication with the upper water pipes 17, respectively. The above-mentioned inlet header 3 is provided in communication with the lower end of the spiral water pipe 19, and the outlet header 5 is provided in communication with the upper water pipe 17. The inlet header 3 is provided independently for each spiral water pipe 19 or for each arbitrary number. A manifold 2 that distributes the water supplied from the economizer 7 to each inlet header 3.
1 is formed. Also, economizer 7 and manifold 2
1 and a branch pipe 25 connecting the manifold 21 to each of the inlet headers 3.

Further, the furnace ceiling wall 27, the screen tube 2
9. Similar water pipes and pipes and headers for supplying water to the water pipes are provided also in the components of the boiler other than the furnace wall, such as the sub-side walls 31 and 33. Also, a superheater spray, which is a desuperheater for adjusting the temperature of water and steam, may be provided as appropriate. The configuration of such a boiler device is well known to those skilled in the art.

The features of the embodiment are described below. First, a variable orifice 35 is provided in each of the branch pipes 25 extending from the manifold 21 to each of the inlet headers 3. This variable orifice is well known,
The pressure loss can be arbitrarily controlled by adjusting the flow path area of the throttle portion. In addition, front wall 9 and rear wall 1
1, metal part 3 at the upper end of left side wall 13 and right side wall 15
6, a temperature sensor 37 is provided at intervals of each upper water pipe 17 along the upper edge of the furnace wall.

The operation and function of the boiler device of this embodiment will be described. The boiler furnace is heated to a high temperature by burning the burner 10 and introducing air from the after-air port 12 as necessary. Then, water, which is a medium for transmitting the thermal energy of the furnace to other equipment such as a turbine, is supplied from the economizer 7 to the pipe 23, the manifold 21,
The spiral water pipe 1 passes through the branch pipe 25 and the variable orifice 35 provided in the middle thereof and the inlet header 3.
9. Then, while passing through the spiral water pipe 19 and the upper water pipe 17, the water is heated by heat transfer from the furnace through the furnace wall and the water pipe, and high-temperature and high-pressure steam is extracted from the outlet header 5. Then, this steam is supplied to another device such as a turbine.

During operation, the temperature of the furnace wall is monitored by a plurality of temperature sensors 37. Then, the average value of the measured values of the furnace wall temperature by these temperature sensors is calculated, and water is supplied to a water pipe near the equivalent temperature sensor 37 for the temperature sensor 37 indicating a higher temperature than the average value. Operating the variable orifice 35 of the branch pipe 25 to increase the flow rate,
Control is performed to decrease the temperature of the furnace wall in the corresponding portion by increasing the amount of heat transfer from the furnace wall to the water tube. Conversely, when there is a temperature sensor 37 at a temperature lower than the average value, the pressure loss of the corresponding variable orifice 35 is increased to reduce the flow rate,
Raise the temperature of the furnace wall in the corresponding part by reducing the amount of heat transfer from the furnace wall to the water tube. In this way, the furnace wall temperature can be partially controlled by adjusting the variable orifice associated with the water pipes provided in such sections, so that the temperature of each section of the furnace wall is averaged, respectively. , The imbalance in the furnace wall temperature can be reduced.

As described above, according to the present embodiment, a variable orifice is provided in the branch pipe for supplying water to the water pipe, and the flow rate thereof is controlled, so that the imbalance in furnace wall temperature can be reduced. Thus, problems such as damage to the furnace wall due to the temperature distribution and an increase in life consumption can be reduced.

Further, by providing the temperature sensor, the actual furnace wall temperature can be fed back to the control of the variable orifice, and the reliability of the furnace wall temperature control can be ensured.

Further, in this embodiment, the control of each variable orifice is controlled so that the furnace wall temperature of the corresponding portion approaches the average value of the furnace wall temperature measured by each temperature sensor. Instead, control may be performed so as to approach an arbitrarily set target furnace wall temperature.

In this embodiment, the temperature sensor is provided on the metal part at the upper end of the furnace wall.
The temperature sensor can be provided at any place on the furnace wall around the relevant water pipe.

Further, in the present embodiment, the variable orifices are provided in all the branch pipes, but the variable orifices may be provided in only some of the branch pipes if necessary.

In the present embodiment, the variable orifice is used as a variable flow control means. However, other known flow control means capable of changing the flow rate in the branch pipe may be used.

[0020]

According to the present invention, the imbalance in the furnace wall temperature of the boiler device can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a boiler device to which the present invention is applied.

FIG. 2 is an exploded view of a furnace wall of the boiler device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace wall 3 Inlet header 5 Outlet header 7 Energy saving device 17 Upper water pipe 19 Spiral water pipe 25 Branch pipe 35 Variable orifice

Claims (3)

[Claims] 1. A plurality of water pipes extending along a furnace wall of a furnace, water supply means for supplying water to the water pipes through branch pipes respectively connected to the plurality of water pipes, and A boiler device having variable flow rate control means provided in a predetermined branch pipe. 2. The boiler apparatus according to claim 1, further comprising temperature measuring means for measuring a temperature of a furnace wall near a water pipe to which water is supplied by the predetermined branch pipe. 3. A plurality of water pipes extending along a furnace wall of a furnace, water supply means for supplying water to the water pipes via branch pipes respectively connected to the plurality of water pipes, and A method for controlling a boiler apparatus, comprising: a variable flow rate control means provided in a predetermined branch pipe; and a temperature measurement means for measuring a furnace wall temperature near a water pipe supplied with water by the predetermined branch pipe. The flow rate of the water pipe is controlled by controlling the flow rate control means so that the furnace wall temperature approaches the set target furnace wall temperature, and the amount of heat transfer from the furnace wall to the water pipe is increased or decreased to control the furnace wall temperature. A boiler device control method for reducing imbalance.