JP2580068Y2 - Water supply abnormality detector for multi-tube once-through boiler - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply abnormality detecting device for detecting a decrease in capacity of a water supply pump and clogging of a water supply strainer.

[0002]

2. Description of the Related Art In water supply to a boiler, if the capacity of a water supply pump is reduced or if a water supply strainer is clogged, the water supply speed is reduced, so that repair or the like is required. As a method of judging a water supply abnormality, there has been a method of measuring a water supply pump operation time and displaying that an abnormality has occurred in a water supply system or stopping combustion when the operation time becomes longer than an allowable time.

[0003] Also, whether the cause of the abnormality is in the water supply pump,
If it is possible to know in advance whether or not the water supply strainer is present, the labor required for repairs and the like can be greatly reduced, and JP-A-2-293504 is disclosed as a method for detecting an abnormal portion. Japanese Patent Application Laid-Open No. 2-293504 compares chronological changes in the operation time of a water supply pump. If the operation time changes slowly over a long period of time, the capacity of the water supply pump decreases. It is determined. However, when determining the cause by the above method, it is necessary to memorize the operation time of the water supply pump over time, a long period of time is required to identify the cause, and the deterioration of the water supply pump and the water strainer If the clogging of the water supply proceeded at the same time, or if the capacity suddenly decreased due to an abnormality in the water supply pump, the cause could not be specified correctly.

[0004]

The problem to be solved by the present invention is to provide a water supply abnormality detecting device capable of specifying the cause of the abnormality.

[0005]

The water level in the boiler is detected by a water level detecting device, and water is supplied to the boiler by a water supply pump provided in a water supply line in which a water supply strainer is inserted. An electrode rod for blowing is provided at the bottom, and the water level control device controls the water supply pump ON / OFF by a signal from the water level detecting device to control the water level in the can to a predetermined level, and the entire electrode is blown by the electrode electrode for blowing. In the multi-tube once-through boiler detecting the execution of the above, if the continuous operation time of the water supply pump in the normal water supply performed when the water level is lowered by the combustion is longer, the time when it is determined that there is a possibility of abnormality is T1. If the continuous operation time of the water supply pump in the water supply after the entire blow is longer than that, the time when it is determined that there is a possibility of abnormality is set as T3, and the signal from the blow electrode rod is set. It judges whether it is the normal water supply during combustion or the water supply after all the blows. In the case of the normal water supply, when the actual continuous operation time of the water supply pump is T1 or more, the display of the water supply pump check is displayed. When the actual water supply pump continuous operation time is equal to or longer than T3, the water supply strainer inspection is displayed.

[0006]

[Function] When the feedwater pump is reduced in capacity, if the pressure inside the boiler is high, the water supply time will be significantly longer, but if the pressure inside the boiler is low after full blow, the pressure inside the boiler will be longer. Rather than a significant increase as in the case of high,
Water can be supplied with a relatively small increase. Even when the water supply strainer is clogged, the water supply time becomes longer, but in this case, even if the pressure becomes higher, the water supply time does not increase so much as when the pump capacity decreases. If the capacity of the water supply pump is reduced, the water supply time becomes longer at the time of normal water supply. If the water supply time becomes longer than T1 at the time of normal water supply, the capacity of the water supply pump is reduced. If the water supply time after all the blows becomes longer than T3 before the length becomes longer, it can be specified that the water supply strainer is clogged.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 is a schematic diagram, in which combustion of a boiler (1) is controlled by opening and closing a solenoid valve (4) by a signal from a combustion control device (2). The water supply is sent into the boiler through a water supply strainer (5), a water supply pump (6) and a check valve (7), and the water supply control is connected to a brackish water separator (8) and a lower header (3). The operation is performed by a water level control circuit (10) to which a signal from the detected water level detection device (9) is sent, and a feed water pump operation signal is output so that the water level becomes constant. An electrode rod (11) is provided for detecting the presence or absence of water at the bottom of the boiler and detecting that all the blow has been performed when the water at the bottom is exhausted. In order to judge whether the water supply is due to the water supply for the air blow or the full blow, the electrode rod (1
A signal indicating whether or not 1) detects the presence of water is sent to a water supply abnormality determination circuit (12). The discrimination circuit is on the display panel (1
3) and connected to the combustion control device.

[0008] Water supply to the boiler is divided into normal water supply and water supply after all blows according to the state of the boiler. Normal water supply is water supply that is performed until the water level reaches the upper limit when the can water evaporates due to the combustion of the boiler and the water level reaches the lower limit. At this time, the pressure in the boiler is increasing, and when the capacity of the water supply pump is reduced, the water supply speed is extremely reduced, so that the time required for water supply is greatly increased. Also,
In the boiler, all the blows for draining all the canned water are periodically performed. In the case of water supply after all the blows, the water is blown from a state where there is no canned water until the water level reaches the upper limit. At this time, the inside of the boiler is empty, the pressure is almost equal to the atmospheric pressure,
Even if the capacity of the water supply pump is reduced, the water supply speed does not decrease as much as when water is supplied into the high pressure boiler,
The water supply time does not change as much as when the pressure in the boiler is high. In addition, when the water supply strainer is clogged, the water supply time for both normal water supply and water supply after full blow is similarly long, and the water supply time does not become extremely long even if the pressure inside the boiler increases. .

[0009] The feed water abnormality judging circuit supplies a continuous operation time of the feed water pump in the normal feed water during combustion, a time T1 when there is a possibility that there is a possibility of an abnormality, and a time T2 when the supply of water continues and it is determined that the water is abnormal. Also, in the case of the water supply pump operating time after the full blow, a time T3 at which there is a possibility that there is a possibility of an abnormality if it is longer than that, and a time T4 at which water supply continues and it is determined that the water supply is abnormal are input. At the start of water supply, the water supply abnormality determination device determines whether the water supply is normal water supply or water supply after all the blows, based on a signal from the blow timing detection electrode rod, and measures the time during which the water supply operation signal is output. In the case of normal water supply, when the water supply time becomes T1 or more, the water supply pump check is displayed on the display panel, and when the water supply continues and the water supply time reaches T2, a signal is sent to the combustion control device to stop the operation of the boiler and display. Outputs a water supply pump error to the panel. In the case of water supply after all blows, when the water supply time becomes T3 or more, the water supply strainer inspection is displayed on the display panel. When the water supply continues and the water supply time reaches T4, a signal is sent to the combustion control device to stop the operation of the boiler. And outputs a water strainer error to the display panel.

[0010]

[Effect of the Invention] By implementing the present invention, it is possible to specify where the cause of the occurrence of the abnormality is.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiler main body 2 Combustion control device 3 Lower header 4 Fuel solenoid valve 5 Water supply strainer 6 Water supply pump 7 Check valve 8 Brackish water separator 9 Water level detection device 10 Water level control circuit 11 Blow timing detection electrode rod 12 Water supply abnormality discrimination circuit 13 Display panel

Claims (1)

(57) [Scope of request for utility model registration] The water level in a boiler is detected by a water level detecting device, and water is supplied to the boiler by a water supply pump provided in a water supply line having a water supply strainer inserted in the middle thereof, and a blower is provided at a bottom of the boiler. The water level control device turns on the water supply pump in response to a signal from the water level detection device.
In the multi-tube once-through boiler in which the water level in the can is controlled to a predetermined level by performing OFF control and the execution of all blows is detected by the electrode for blowing, in the case of normal water supply performed when the water level is lowered by combustion. If the continuous operation time of the water supply pump is longer than that, it is determined that there is a possibility that the abnormality is likely to be T1. If the continuous operation time of the water supply pump in the water supply after all blows is longer than that, it is determined that there is a possibility of the abnormality. Time is set as T3, and it is determined whether the water supply is the normal water supply during combustion or the water supply after all the blows based on the signal from the blowing electrode rod. When T1 or more, display the feedwater pump check, and when water is supplied after all blows, display the feedwater strainer check when the actual water supply pump continuous operation time is T3 or more. Water supply abnormality detecting device of a multi-tube once-through boiler, wherein.