JPH0730887B2 - A method for detecting abnormal points of water supply capacity deterioration in boiler water supply systems - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for detecting an abnormal point of a decrease in water supply capacity in a water supply system of a boiler, and particularly to an evaporation amount of several hundred kg / h to several to
The present invention relates to a method for detecting an abnormal point of a decrease in water supply capacity in a water supply system of a small boiler of n / h.

[Conventional technology]

Conventionally, as a method of detecting an abnormality in the reduction of the water supply capacity in the water supply system of a boiler having a water supply pump in the water supply system, for example, the water supply time of the water supply pump is measured each time the water supply pump is differential, and the measured value of this water supply time is used. There is a device that compares with a preset water supply time and determines that the water supply capacity of the water supply pump has deteriorated when the measured value of the water supply time is equal to or greater than the set value.

[Problems to be Solved by the Invention]

However, the cause of the decrease in the water supply capacity of the boiler water supply system is not only the decrease in the water supply capacity of the water supply pump, but also cavitation, air biting, or clogging of the water supply strainer. In this case, the decrease in water supply capacity of the water supply pump is not always the cause, and it is not possible to determine which of the above causes the water supply capacity of the water supply system has deteriorated, and it is not possible to take time-consuming and prompt measures to detect abnormal points. There were many

In view of the above problems, the present invention provides a method for detecting an abnormal location of a decrease in the water supply capacity of a boiler water supply system that can accurately detect an abnormal location when an abnormality occurs in the water supply capacity of a boiler water supply system. It is intended to be provided.

[Means for Solving the Problems]

In order to achieve the above object, the method for detecting an abnormal portion of a decrease in water supply capacity in a boiler water supply system according to the present invention stratifies the cause of an abnormal occurrence of a decrease in water supply capacity of a boiler having a water supply pump in the water supply system. (Distinguish by item), operation for grasping beforehand the change pattern of water supply time by water supply pump until abnormal occurrence of water supply capacity deterioration occurs for each stratified cause, and water supply pump during operation of this boiler Of the water supply time of the boiler and comparing the temporal change pattern of the actually measured water supply time of the water supply pump with the change pattern of the water supply time of each stratified cause. This includes an operation of detecting an abnormal location where the performance is deteriorated.

Next, a method of detecting an abnormal portion of a decrease in water supply capacity of the boiler water supply system according to the present invention will be described in detail.

According to the experience of the present inventors, the main causes of the decrease in the water supply capacity in the water supply system of the boiler including the water supply pump are, as described above, the decrease in the water supply capacity of the water supply pump, cavitation and air. Bite and blockage of water feed strainer are raised. According to the confirmation based on these causes, the state until the water supply capacity decreases for each of these causes is that if the cause is a decrease in the water supply capacity of the water supply pump, It gradually increases and then slowly decreases over a long period of several months,
If the cause is clogging of the water strainer, it will decrease in a relatively short period of time from a few days to a few weeks, and if the cause is cavitation or air bite, it will decrease in a very short period of a few hours to a few days. confirmed.

Therefore, the change pattern until the water supply capacity decreases for each cause of the decrease in the water supply capacity, which has been grasped in advance in this way, and the temporal change pattern of the required water supply time of the water supply pump measured during the operation of the boiler. By comparing the above, it is possible to accurately detect the location where the abnormality in the water supply capacity is deteriorated, and quickly repair the location where the abnormality occurs. The time-dependent change pattern of the required water supply time of the water supply pump that is actually measured may be the time-dependent change pattern of the actual measurement value, but it may be due to a special cause such as overload or sudden opening / closing of the main steam valve. In order to eliminate temporary changes, it is preferable to use the average value of the values measured several times or the temporal change pattern based on the average value excluding the maximum and minimum values.

〔Example〕

Embodiments according to the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram of a device for detecting an abnormal portion of a decrease in water supply capacity in a water supply system of a boiler according to the present invention.

1 is a small once-through boiler, 2 is a boiler main body, 3 is a burner provided on the upper portion of the boiler main body 2, 4 is a steam pipe connected to a water pipe header (not shown) inside the boiler main body 2, and 5 is a boiler. A water supply pipe line connected to a sewer pipe header (not shown) inside the main body 2, 6 denotes a water level detector connected to the water pipe header and the sewer pipe header inside the boiler main body 2, The water supply pipe line 5 is provided with a flow meter 7, a water supply pump 8, and a check valve 9 in order from the upstream side. The water level detector 6 is, as shown in an enlarged view in FIG.
The water level detecting cylinder 12 is connected to the water level detecting position between the water level detecting cylinders 12, and the water level detecting cylinder 12 has an upper lid 13 for stopping the water level detector 14, the water level detector for starting water supply 15, and the water level detector for detecting an abnormally low water level. 16
3 water level detectors are provided. In addition, in this example, the outputs from these three water level detectors 14, 15, 16 are configured to be input to the water level controller 17, and the water supply stop water level detector 14 and the water supply start water level detector are also provided. At the same time that the water supply pump 8 is activated / stopped by the signal from 15, the time from the activation of this water supply pump 8 to its stoppage is controlled by the water level controller.
It is configured to measure at 17.

When the method of the present invention is carried out in the device having the above-mentioned configuration, it is possible to cope with the deterioration of the water supply capacity of the water supply pump, which is the main cause of the deterioration of the water supply capacity, the cavitation and the air bite, and the clogging of the water supply strainer, which are the main causes of the water supply capacity deterioration. The water level controller indicates the change pattern until the water supply capacity
Enter in 17 to set. During operation of the boiler, signals from the water level detector 14 for stopping water supply and the water level detector 15 for starting water supply of the water level detector 6 are supplied via the water level controller 17 to the water supply pump 8.
While controlling the operation and stop of the water supply, the water level controller 17 measures the time from the operation of the water supply pump 8 to the stop, and the measurement result is temporally stored in the water level controller 17,
In addition, at each measurement, the change pattern of the time required for water supply stored over time and the change pattern until the water supply capacity that has been input in advance are decreased are compared, and as a result of the comparison, In the case of corresponding to any of them, an alarm is issued according to the corresponding cause, whereby an abnormal portion of the decrease in water supply capacity in the water supply system of the boiler 1 can be accurately detected.

〔The invention's effect〕

As described above, according to the method of the present invention, when the water supply capacity of the boiler is lowered, it is possible to detect an abnormal portion of the water supply system without any trouble, and therefore, the repair time is shortened and the operation rate of the boiler is improved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a device for detecting an abnormal portion of a reduced water supply capacity in a boiler water supply system according to the present invention, and FIG. 2 is an enlarged sectional view of a water level detector according to the present invention. 1 ... Small once-through boiler, 2 ... Boiler body 3 ... Burner, 4 ... Steam pipe 5 ... Water supply line, 6 ... Water level detector 7 ... Flowmeter, 8 ... Water supply pump 9 ... Reverse Stop valve, 10, 11 ... Communication pipe 12 ... Water level detector cylinder, 13 ... Top 14 ... Water level detector for stopping water supply 15 ... Water level detector for starting water supply 16 ... Water level detector for detecting abnormally low water level 17 ... Water level controller

Claims (1)

[Claims] 1. A method for detecting an abnormal point of a decrease in water supply capacity in a water supply system of a boiler having a water supply pump in a water supply system, comprising an operation of stratifying a cause of an abnormal occurrence of a decrease in water supply capacity of a boiler, Operation to grasp the change pattern of the water supply time by the water supply pump until abnormal occurrence of water supply capacity deterioration occurs for each separated cause, and operation to measure the required water supply time of the water supply pump during operation of this boiler, and It is characterized by including an operation of detecting an abnormal portion of the water supply system of the boiler by comparing the temporal change pattern of the actually required water supply time of the water supply pump with the change pattern of the water supply time for each of the stratified causes. Of abnormal water supply capacity in boiler water supply system.