JPH07217872A - Water level controller for boiler and blow device employing the water level controller - Google Patents

Abstract

PURPOSE:To prevent the abnormal lowering of boiler water level and enable blowing to be surely conducted when the boiler water is condensed by a method wherein the timing of blowing is detected and the blowing is effected when the lowering of water level is generated frequently. CONSTITUTION:When an electrode rod EK has detected no water, a feed water pump 7 is operated and a low water level warning is outputted. The detection of the timing of blowing when the blowing is not effected and the condensation of boiler water in a boiler 1 has advanced is effected by the deciding device 11 of the timing of blowing and when the no-water detection of the electrode rod EK during a given period of time has effected by a frequency or more, the timing of blowing is outputted whereby a blow solenoid valve 10 is operated by a blow controller 13 and blowing is effected. According to this method, the abnormal lowering of the water level of the boiler 1 can be prevented and when the boiler water is condensed, the blowing can be effected surely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler water level controller and a blower using the water level controller.

[0002]

2. Description of the Related Art Boiler water level control is carried out by using an electrode rod provided on a water level detecting cylinder to stop water supply E1 and start water supply E
2. The presence or absence of water at each of the combustion stop water levels E3 is detected, water supply is started when water is detected at water level E2, water supply is stopped when water is detected at water level E1, water level E3 is detected at no water. When it does, the combustion of the boiler is stopped. Normally, the water level is kept between E1 and E2, but the electrode rod may detect the presence of water even when there is no water due to the presence of electrolytic sludge. In that case, water is not supplied. The water in the can sometimes dropped abnormally.

In addition, when the boiler continues to evaporate water, the electric conductivity and PH of boiler can water rises, or dissolved solids are concentrated, and further, sludge and insoluble solids are generated on the heat transfer surface and the can bottom. Due to the accumulation, various problems such as carryover, corrosion, reduction of heat transfer efficiency, and overheating of the can body occur. Therefore, in order to eliminate the above problems, can water is blown. However, if the number of blows is too large, corrosion is caused due to an increase in dissolved oxygen and a decrease in PH. Therefore, it is necessary to properly determine the blow timing and perform the blow. As a method to detect the blow time,
There is a method of providing a conductivity detector for detecting the conductivity of canned water and detecting the blow timing by the conductivity. in this case,
The conductivity detector requires frequent maintenance, and if maintenance is insufficient, it may not be possible to detect the blow time even if the concentration of the can water progresses. In some cases, the blow valve could not be blown due to a defect in the blow valve or the like.

[0004]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to develop a blower device which prevents abnormal reduction of can water and detects the blow time by a method different from the conventional method to surely blow. To do.

[0005]

[Means for Solving the Problems] An electrode rod for detecting the presence or absence of water at a low water level warning water level EK, which is between the water level E2 and the water level E3, is provided, and the water level becomes lower than EK in addition to the normal water level control. At this time, operate the water supply pump for a certain period of time. Further, in the water level detection cylinder in which the steam separator and the lower head are connected by piping, the presence or absence of water at the water level E2 at which normal water supply is started and the water level E1 at which water supply is stopped is detected, and A water level detection device that can detect the presence or absence of water at the water level EK, which supplies water for a certain period of time to prevent low water levels, is provided in the water level detection cylinder that connects the lower head of the pipe with the water level within a certain period of time. Is connected to a blow timing detection device that has a counting device that measures the number of times when the water level drops below EK, and when the water level frequently drops, the blow timing is detected and Open the blow valve and blow.

The blow timing detecting device and a blow sensor for detecting the blow timing by electric conductivity are used together, and blow valves corresponding to the blow timing detecting device and the blow sensor are provided in parallel, and independent blow devices are provided.

[0007]

When the water level becomes less than EK because water is not supplied due to an abnormality in the electrode rod that detects the presence or absence of water at the water level E2 and water level is below EK, what is E2? Separately, water is supplied for a certain period of time, so it is possible to prevent an abnormal drop in water level.

As the concentration of canned water progresses, phenomena called priming and forming occur. When priming and forming occur, the can water is pulled up to the steam separator together with the steam. Therefore, a water level detection cylinder for detecting the water levels E1 and E2 is installed in the pipe connecting the steam separator and the lower head, and the water level EK is set. If a water level detection tube for detection is provided in the pipe connecting the upper and lower heads, the water level in the water level detection tube connected to the upper head and the lower head will drop even if the water level is E2 or higher. However, since the water level frequently drops to EK or lower, it can be seen that the can water is concentrated.

When the blow timing detecting device and the blow sensor are used together, the blow valves corresponding to the blow timing detecting device, the blow sensor, and the blow valve are connected in parallel, so that an abnormality occurs in any of the blow timing detecting device, the blow sensor, and the blow valve. However, the blow can be surely performed.

[0010]

An embodiment of the present invention will be described with reference to the drawings.
The boiler (1) has an upper header (2), a lower header (3) and a number of water pipes (4), and steam is sent from the upper header to a steam separator (5) where it is separated into gas and liquid. The steam is returned to the steam using equipment (not shown), the water contained in the steam is returned to the lower head by the downcomer pipe (6), and the water supply is supplied to the lower head by the water supply pump (7). Electrode rods E1 and E are attached to the water level detector connected to the steam separator and the lower head.
2. Electrode rods EK and E3 are provided in the water level detection cylinders connected to the upper and lower pipe heads, and the electrode rods EK go through the blow timing determination device, and the other electrode rods directly feed the water level control device ( 12).

The water level controller operates the water feed pump when the electrode rod E2 detects the absence of water, stops the water feed pump when the electrode rod E1 detects the presence of water, and turns on the boiler when the electrode rod E3 detects the absence of water. When it is stopped and the electrode EK detects that there is no water, the feed pump is operated and a low water level notice is output for a set time. In normal detection of the blow time, the concentration of the blow is measured by a blow sensor (8) provided in the downcomer, and when the concentration becomes equal to or higher than the measured value, the blow time is output. The detection of the blow timing by the water level detection device, which is performed when the concentration is advanced without the blow, is performed by the blow timing determination device (11) that measures the combustion time and the number of times water is detected in the electrode EK. When the water-free detection of the electrode rod EK is performed more than the set number of times within a certain period of time, the blow timing is output, and the blow device abnormality is also output. The blow pipe connected to the downcomer pipe is branched midway, and the first blow solenoid valve (9) and the second blow solenoid valve (10) are inserted in the parallel portions, respectively.

When performing blow, a blow control device (1
When the blow solenoid valve is operated from 3) and the blow sensor detects the blow timing and blows,
When the blow timing is detected by the first blow solenoid valve and the determination device and the blow is performed, the blow is performed using the second blow solenoid valve. If the blow is performed in a state where the water level is low, the water level further decreases, and there is a possibility that the low water level becomes abnormal. Therefore, the blow is performed when the water level returns to E1.

[0013]

EFFECTS OF THE INVENTION It is possible to prevent an abnormal decrease in the water level due to an abnormality in the water level control device, and it is possible to surely perform blowing when the can water is concentrated.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram of an embodiment of claim 1 of the present invention.

[Explanation of symbols]

1 Boiler 2 Upper heading head 3 Lower heading head 4 Water tube 5 Steam separator 6 Precipitation tube 7 Water supply pump 8 Blow sensor 9 First blow solenoid valve 10 Second blow solenoid valve 11 Judgment device 12 Water level control device 13 Blow control device E1 Electrode rod that detects the water supply stop water level E2 Electrode rod that detects the normal water supply start water level E3 Electrode rod that detects the combustion stop water level EK Electrode rod that detects the water level that supplies water for a certain period of time to prevent low water levels

Claims (3)

[Claims] 1. An upper body and a lower body are connected by a number of vertical water pipes to form a can body. A water supply pipe having a water supply pump inserted in the middle of the lower body is connected to the outside of the boiler. Water supply stop water level E by the electrode rod in the water level detection cylinder provided
1. In the water level control device that supplies water to the boiler by detecting the presence or absence of water at the water supply start water level E2 and controlling the operation of the water supply pump by the detected water level, the low water level is lower than the water level E2. An electrode rod that detects the presence or absence of water at the water level EK is provided, and the water level is EK separately from the normal water level control.
A water level control device for a boiler, wherein the water supply pump is operated for a certain period of time when the water level falls below a certain level. 2. The boiler having the water level control device according to claim 1, wherein a blow pipe having a blow valve is provided at a lower portion of the boiler, and a steam separator and a lower pipe header connected to the upper header are provided. Water level detection device that detects the presence or absence of water at the water level E1 and water level E2 in the middle of the pipe that connects the pipes, Water level detection device that detects the presence or absence of water at the water level EK in the middle of the pipe that connects the upper pipe header and the lower pipe header, constant combustion A blower blower characterized by being provided with a counting device for detecting the number of times water level EK is detected in the time of no water, and when the water level frequently falls below EK, the blow valve is opened to blow. 3. A blow device for detecting the blow timing by detecting the water level according to claim 2, and a blow sensor for detecting the blow timing according to the concentration of can water.
A blower blower characterized in that blowers can be reliably carried out by providing corresponding blow valves in parallel and by providing independent blowers in parallel.