JP2002235921A - Boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify one of a plurality of air prepreheaters(AH) having the highest degree of clogging even when the gas inlet duct and gas outlet duct of each preheater are collected to form one system. SOLUTION: The boiler comprises one forcing ventilator and one system of air duct at the boiler inlet, a plurality of systems each having an air preheater 3 disposed between the forcing ventilator 1 and the boiler inlet are provided, an air flow rate detector 11 is disposed at the air inlet or outlet side of each air preheater, and the degree of clogging of each air preheater 3 is determined based on the difference of air flow rate detected by each air flow rate detector. Alternatively, in the boiler comprising one forcing ventilator 1 and a system of air duct at the boiler inlet, two systems each having an air preheater 3 are provided and clogging of two AHs is detected based on the air flow rate detected by only one detector disposed at the air inlet or outlet side of air preheater in one of two systems.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler apparatus having a plurality of air preheaters (hereinafter, referred to as AHs (Air Heaters)) and one push-in ventilator (hereinafter, referred to as FDF). The present invention relates to a flue duct system, and can be suitably used particularly for a method of specifying which AH among a plurality of AHs is most frequently clogged due to adhesion of ash or the like.

The AH handled in the present invention is a regenerative heat exchange type AH (rotary air preheating type AH), and is not intended for an AH in which preheated air and exhaust gas are completely separated.

[0003]

2. Description of the Related Art An element which is an internal structure of an AH is clogged in a regas (combustion exhaust gas) and an air circulation portion (a heating portion of preheated air) due to adhesion of combustion ash and the like, and an inlet duct and an outlet duct of the AH are generated. The pressure difference is increased, and the FDF discharge pressure rises. If the air blower (IDF) is provided, the IDF operation pressure is increased.

In order to continue the operation of the boiler, it is necessary to keep the increase in the pressure loss of the air and gas systems within the discharge capacity of the FDF or IDF. Therefore, the pressure difference between the gas inlet duct and the gas outlet duct of the AH is required. When a certain value is exceeded, A
It is necessary to clean the H element and reduce the pressure difference.

[0005] As a conventional method for detecting clogging of the AH element portion, for example, there is a method shown in FIG. That is, in the related art, the clogging of the AH element portion is detected by detecting the rise of the difference between the gas inlet duct and the gas outlet duct of the AH 3 by the AH gas side differential pressure detector 10.

In the prior art, only the furnace inlet combustion air required for combustion and performance management in the boiler is grasped, and no AH secondary inlet air flow rate detection is provided. In general, when a plurality of AHs are installed, the same number of FDFs are installed, and the air flow and the gas flow of each system are generally equalized, or the operation is performed by grasping each flow. Was. That is, in the prior art, as shown in FIG. 2, a forced air ventilator 1 is provided for each line of preheated air, and a secondary air flow rate detector 12 is provided at a furnace inlet of the preheated air, and the detected flow rate from the detector is determined. Boiler combustion management was implemented. The secondary air flow detector 12 was used for boiler combustion management.

[0007] In addition, IPP (Ind
Boiler equipment as an independent Power Producer (plant) plant is required, and the system configuration of a boiler equipment that requires a stable supply of rated electrical output in a small scale, such as wholesale power supply or supply to the steel industry, is required. Only a plurality of AHs that need to be cleaned are now installed (a plurality of AHs instead of one AH for one FDF). That is, in order to stably supply electric power, instead of completely stopping the AH element and cleaning the element when the AH element becomes clogged, the power can always be stably supplied even in one-lung operation. Two or more AHs are installed. Here, A which needs cleaning
Even if H is stopped, one-lung operation can be performed with another AH in which clogging has not yet occurred.

[0008]

SUMMARY OF THE INVENTION In the prior art, 1
In the case of a boiler device equipped with FDF and AH for each
The passing air flow rate of H can be grasped as the flow rate of air supplied from each FDF, and when the passing air flow rate of each AH is equal, if the degree of clogging due to ash adhesion to each AH element is different, each AH Since the pressure difference between the air and gas inlet / outlet ports differs from that in FIG.
If detected by the H gas side differential pressure detector 10, it can be specified that AH having the highest differential pressure has the largest amount of clogging due to ash adhesion.

On the other hand, in the case of a boiler apparatus having two AHs and one FDF, the AH air inlet duct naturally branches from one line to form two lines,
Connect to The AH air outlet ducts merge after leaving each AH. For this reason, even if the degree of clogging of the AHs is different, the ratio of the air flow passing through each AH is changed to be in a balanced state, and the inlet / outlet pressure difference of each AH becomes the same value, and the pressure difference Cannot detect clogging.

In addition, the number of IDFs is one, or
In the case where the gas flow rate ratio changes on the gas side as in the case of the air side and balances, the clogging is detected by the gas pressure difference in the AH as described above. Can not.

When the degree of clogging of the AH element is high, the air flow rate and the gas flow rate are similarly low, but the heat exchange amount at the AH is low. There is almost no apparent change depending on the degree. Therefore, it is difficult to grasp the degree of AH clogging from the temperature characteristics.

In view of the above, according to the present invention, even when the gas inlet duct and the gas outlet duct of each AH are gathered to form a single system, any one of the plurality of AHs has the highest degree of clogging. It is intended to specify whether or not the AH pressure difference measuring device is used. Another object is to reduce the number of clogging detectors when the number of AHs is two.

[0013]

In order to solve the above problems, the present invention employs the following configuration. A boiler apparatus having one forced draft fan and having one series of air passages at a boiler inlet, wherein a plurality of series of air preheaters are provided between the forced draft fan and the boiler inlet, respectively. A boiler device provided with an air flow detector on the air inlet side or the air outlet side of each air preheater, and judging the degree of clogging of each air preheater based on the difference in air flow detected by each air flow detector .

A boiler apparatus having one forced draft fan and one series of air passages at the boiler inlet, wherein air preheaters are respectively installed between the forced draft fan and the boiler inlet. Two lines are provided, and only one air flow detector is provided on the air inlet side or the air outlet side of one air preheater of the two lines, and the air flow detected by the only air flow detector and two air preheats are provided. 2 based on the total air flow of the vessel
Boiler device that determines the degree of clogging of two air preheaters.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A boiler device according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a diagram showing a specific configuration of a boiler device according to an embodiment of the present invention, where 1 is a forced draft fan, 2 is an AH secondary air inlet tamper,
Is an air preheater (AH), 4 is an AH secondary air outlet tamper,
5 is a furnace, 6 is an AH gas inlet tamper, 7 is an AH gas outlet damper, 8 is an AH bypass damper, and 9 is an induction ventilator (ID
F), AH gas side differential detector 10, AH inlet secondary air flow detector, 12 represents furnace inlet secondary air flow detector.

A feature of the embodiment of the present invention is that a secondary air flow detector 11 is installed at the secondary air inlet side of each AH 3 so that the secondary air flow flowing into each AH 3 can be detected. Then, the difference in the degree of clogging between the two series can be determined based on the difference between the detected flow rates. FIG. 1 showing the present embodiment exemplifies a boiler configuration in which one FDF installs two AHs at one furnace entrance, but is not limited to two AHs, and a plurality of AHs are installed and each AH is installed. By sequentially comparing the inlet secondary air flow rates, it is possible to detect the degree of clogging at each AH.

Next, another embodiment of the present invention is characterized in that, in the configuration example shown in FIG. 1, instead of installing the secondary air flow rate detectors 11 in two AH systems, one AH system is used. The configuration is such that the secondary air flow detector 11 is installed only on Here, the secondary air flow rate at the furnace inlet (the flow rate detected by the furnace inlet secondary air flow rate detector 12 in FIG. 1) or the FDF measured for the combustion management of the normal boiler device is used.
From the air flow rate of the entire boiler indirectly obtained from the characteristics, that is, the total air flow rate of the two series of AHs, and the flow rate detected from the secondary air flow rate detector 11 of the one AH series only, Can be calculated. Therefore, the degree of AH clogging can be detected by comparing the detected flow rate of one AH with the calculated flow rate of the other.

In another embodiment of the present invention, the number of AH inlet secondary air flow detectors can be reduced.

In the above description, the configuration example in which the secondary air flow rate detector passing through the AH is installed on the inlet side of the AH is illustrated, but the configuration in which the secondary air flow rate detector is installed on the outlet side of the AH can also be the present embodiment (the inlet side). And there is almost no difference in the secondary air flow rate at the outlet side).

[0020]

According to the boiler apparatus of the present invention, the following effects can be obtained. It is possible to specify which one of a plurality of AHs is the most clogged even with a single wind path at the boiler entrance using one FDF (a conventional AH pressure difference measurement device) , Although it is not possible to identify which AH is the most clogged).

Further, it is possible to specify which of the two AH inlets is more clogged simply by installing the AH inlet secondary air flow detector in one AH instead of in the two AHs. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a flue duct of a boiler device according to an embodiment of the present invention.

FIG. 2 is a view showing a conventional boiler flue duct.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 push-in ventilator (FDF) 2 AH secondary air inlet damper 3 air preheater (AH) 4 AH secondary air outlet damper 5 furnace 6 AH gas inlet damper 7 AH gas outlet damper 8 AH bypass damper 9 induction fan (IDF) ) 10 AH gas side differential pressure detector 11 AH inlet secondary air flow detector 12 Furnace inlet secondary air flow detector

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuyuki Yamamoto 6-9 Takara-cho, Kure-shi, Hiroshima Babcock Hitachi Kure Works F-term (reference) 3K023 QA01 QB02 QC04 TA01

Claims (2)

[Claims] 1. A boiler device having one forced draft fan and a series of air passages at a boiler inlet, wherein air preheaters are respectively installed between the forced draft fan and the boiler inlet. A plurality of systems are provided, an air flow detector is provided on the air inlet side or the air outlet side of each air preheater, and the degree of clogging of each air preheater is determined based on a difference in air flow detected by each air flow detector. Boiler device characterized by determining. 2. A boiler apparatus having one forced draft fan and having a series of air passages at a boiler inlet, wherein air preheaters are respectively installed between the forced draft fan and the boiler inlet. Two lines are provided, and only one air flow detector is provided on the air inlet side or the air outlet side of one of the two air preheaters. The air flow detected by the only air flow detector and two air preheats are provided. A boiler device for determining a degree of clogging of two air preheaters based on a total air flow rate of the boiler.