JPH0740808Y2 - Water pump capacity detection device in boiler system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a detection device for detecting a decrease in the capacity of a feed pump in a boiler system.

[Prior Art and Its Problems] A conventional multi-tube once-through boiler system includes a boiler body that connects a lower header and an upper header with a large number of water pipes, a water supply pump that supplies water into the boiler body, and a boiler. A heating mechanism for heating the water supplied into the main body, a water level detector communicating with the boiler body and provided on the outside thereof, and a control for receiving the output signal from the water level detector and controlling the water supply pump and the heating mechanism. Equipped with vessels. In this conventional multi-tube once-through boiler system, the water supply control into the boiler main body is controlled by the water level detector provided outside the boiler main body if the water level in the boiler main body falls to a low set level. When the set level is detected and the output signal activates the water supply pump installed in the water supply line, and when the water level inside the boiler rises and reaches the high set level, the high set level is detected and its output is output. The signal was to stop the water supply pump. In this conventional water supply control method,
The boiler could not operate due to lack of water supply due to the deterioration of the capacity of the water supply pump itself or clogging of the strainer in the water supply pipe, and in the case of excessive water supply shortage, there was a problem such as boiling. In order to solve this problem, conventionally, a method was adopted in which a flow meter and a pressure gauge were provided in the water supply line and the changes in the values were recorded to detect the decrease in the water supply pump capacity or an abnormality in the water supply line. . However, this method requires a lot of manpower and skill, needs to be constantly monitored, and further, these operations are very complicated, and a flow meter and a pressure gauge must be provided in the water supply line. Had a problem with. Further, conventionally, for the purpose of solving the above problems, a water supply pump capacity display device as shown in FIG. 2 is provided. This conventional device includes a boiler body (21), a water supply pump (22), a water level detector (23) having a high setting level electrode (31) and a low setting level electrode (30), and the water level detector (23). ) Receiving the water level signal from
A controller (2) that turns the water supply pump (22) on and off.
In a boiler system including 4), a pressure detecting device (25) is provided for the boiler body (21), and a pressure measuring circuit (26) for measuring the pressure by a signal from the pressure detecting device (25). ), And a measuring circuit (27) that measures the water feed pump operating time from the water feed pump (22) operation signal, and the allowable operating time required for one cycle from ON to OFF If the feed water pump operating time per cycle with respect to the boiler pressure is not longer than the permissible time, it is composed of a discrimination circuit (28) for issuing a signal to that effect and an alarm display (29). The conventional water supply pump capacity detecting means shown in FIG. 2 includes means for measuring one cycle time of the water supply pump (22). However, the boiler system has a drawback that one cycle time of the water supply pump changes depending on the conditions such as the pressure inside the can and the load state, so that it is not possible to accurately detect the performance deterioration.

[Object of the Invention] Therefore, the present invention has been made in order to eliminate the above-mentioned drawbacks of the water supply control system in the conventional boiler system, and it is possible to accurately detect and detect the deterioration of the capacity of the water supply pump in the boiler. An object is to provide a water supply pump capacity detection device.

[Structure of the Invention] In order to achieve the above object, the present invention is, specifically, a boiler main body in which a lower header and an upper header communicate with each other through a large number of water pipes, and a water supply pump for supplying water into the boiler main body. A heating mechanism that heats the water supplied into the boiler body, a water level detector that is provided outside the boiler body and communicates with the boiler body, and a fuel control unit that controls fuel supply to the heating mechanism. A boiler system including a blow control means connected to the boiler body, and a controller for receiving the output signal of the water level detector and controlling the water supply pump, the heating mechanism, the fuel control means, and the blow control means. In the above, based on the evaporation amount per ON time of the water supply pump calculated based on the fuel supply time by the fuel control means and the blow operation time by the blow control means A water supply pump capacity determination circuit for comparing the sum K of blow amounts calculated by the above and the water supply capacity limit value Ko calculated from the set evaporation amount of the boiler is provided, and in the water supply pump capacity determination circuit, K ≦ Ko It is a water supply pump capacity detecting device in a boiler system, characterized in that a decrease in capacity of the water supply pump is discriminated at a certain time.

[Embodiment of the Present Invention] Hereinafter, a water supply pump capacity detection device in a boiler system according to the present invention will be described in detail with reference to specific embodiments shown in the drawings.

As shown in FIG. 1, the multi-tube type once-through boiler device includes a boiler body (1) in which a lower header (2) and an upper header (3) are connected by a number of water pipes (4). Lower header (2) in the boiler body (1)
Is connected to a water supply pump (5) to supply water into the water pipe (4). The water supplied into the water pipe (4) is heated by the heating mechanism (6) and supplied as hot water or steam from the upper header (3) to the external load via the pipe (7). The heating mechanism (6) includes a fuel supply pump (9) provided in the fuel supply line (8), fuel control means such as a fuel control solenoid valve (10), and a burner (11). A blow line (12) is connected to the lower header (2), and the blow amount is controlled by a blow control means such as a blow control solenoid valve (13) provided in the blow line (12). It is designed to be controlled. For the boiler body (1), a pressure detection device (1
4) is provided. On the other hand, in the multi-tube type once-through boiler system, a water level detector (15) communicating with the water pipe (4) is provided outside the boiler body (1) with respect to the boiler body (1). The water level detector (15) has, for example, three first and second lower end heights having mutually different lower end heights.
And a water level detector (15) that includes the third electrode rods (16), (17), and (18) and communicates with the lower end of each electrode rod and the boiler water pipe.
Each water level signal is output by the contact with the water level surface inside. According to the embodiment shown in FIG. 1, when the water surface reaches the first electrode rod (16), a signal for turning off the water supply pump is output, and if the water surface cuts off the second electrode rod (17), the water supply pump When an ON signal is output and the water surface cuts off the third electrode rod (18), a signal for cutting the heating mechanism (6) to a low water level is output. The water level detector (15) is a controller (1
9) is connected to the water supply pump (5), the fuel control solenoid valve (10), and the blow control solenoid based on the output signal of the water level detector (15) and the like via the controller (19). Control each valve (13).

On the other hand, in this invention, first, the sum of the evaporation amount and the blow amount per feed water ON time of the feed pump K [ton / h]
To detect. The sum K of the evaporation amount and the blow amount per ON time of the water supply pump in the water supply pump is calculated by the water supply pump (5).
ON time for the boiler body (1) in the above, that is, the first and second electrode rods (16) of the water level detector (15),
From the ON state of the water supply pump (5) detected by (17) to OF
Water supply time to F and fuel supply time by the fuel control solenoid valve (10) (operation time of the fuel control solenoid valve (10))
And the blow operation time by the blow control solenoid valve (13) (operating time of the blow control solenoid valve (13)). The water supply capacity limit value Ko [ton / h] is calculated from the set evaporation amount of the boiler for the sum K of the evaporation amount and the blow amount per ON time of the water supply pump in this water supply pump. That is, the amount of evaporation and the amount of water supply have a relationship of the amount of evaporation ≈ amount of water supply, but the water supply capacity limit value Ko To Calculate as The rated fuel flow rate is a preset fuel supply amount per unit time.
Therefore, in this invention, in the water supply pump,
Water pump capacity judgment circuit (2 to compare the sum K of evaporation amount and blow amount per ON time and the water supply capacity limit value Ko (2
0) is provided. In the water supply pump capacity determination circuit (20), the sum K of the evaporation amount and the blow amount per water supply pump ON time in the water supply pump and the water supply capacity limit value Ko are compared,
When K> Ko, the capacity of the water supply pump is normal, and when K ≦ Ko, the deterioration of the capacity of the water supply pump is determined and detected.

[Advantage of the Invention] The water supply pump capacity detection device of the present invention having the above-described configuration is provided with a water supply pump capacity determination circuit, and by the determination circuit, the sum of the evaporation amount and the blow amount per water supply pump ON time in the water supply pump is calculated. By comparing K with the water supply capacity limit value Ko, a decrease in water supply pump capacity is detected when K ≦ Ko, and a device such as a flow meter is provided in the water supply pipe as in the conventional case. It is not necessary, and the apparatus can be simplified and the cost can be reduced. Further, it is possible to detect the deterioration of the capacity of the water supply pump by accurately operating even when the situation of the boiler system changes.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a concrete embodiment of a water supply pump capacity detecting device in a boiler system according to the present invention, and FIG. 2 is a schematic block diagram showing an example of a conventional water supply pump capacity detecting device. It is a diagram. (1) …… Boiler body (2) …… Lower header (3) …… Upper header (4) …… Water pipe (5) …… Water supply pump (6) …… Heating mechanism (10) …… Fuel control electromagnetic Valve (13): Solenoid valve for blow control (15): Water level detector (16), (17), (18): Electrode rod (19): Controller (20): Water pump capacity judgment circuit

Claims (1)

[Scope of utility model registration request] 1. A boiler main body in which a lower header and an upper header are connected by a large number of water pipes, a water supply pump for supplying water into the boiler main body, and a heating mechanism for heating the water supplied into the boiler main body. A water level detector communicating with the boiler body and provided outside thereof, fuel control means for controlling fuel supply to the heating mechanism, blow control means connected to the boiler body, and output of the water level detector In a boiler system including a controller for controlling the water supply pump, the heating mechanism, the fuel control means, and the blow control means in response to a signal, water supply calculated based on a fuel supply time by the fuel control means Calculated from the sum K of the evaporation amount per pump ON time and the blow amount calculated based on the blow operation time by the blow control means, and the set evaporation amount of the boiler. A water supply pump capacity determination circuit for comparing the supplied water supply capacity limit value Ko is provided, and when the water supply pump capacity determination circuit is K ≦ Ko, it is determined that the capacity of the water supply pump has deteriorated. Water pump capacity detection device for a boiler system.