JPH0788930B2 - Water supply controller in dual water level control system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-tube type once-through boiler device, and more particularly to a water supply control device in a boiler device that employs a dual water level control system.

(B) Conventional Technology and Its Problems As is well known, the conventional multi-tube once-through boiler device (21) is
Annular lower head (23) and annular upper head (24)
Water is supplied to the water pipe (25) by a water supply pump (26) that is connected to a lower header (23) by a boiler main body (22) that communicates with a plurality of water pipes (25) at predetermined intervals. Then
The water in the water pipe (25) is heated by the gas burner mechanism (27) and supplied as hot water or steam from the upper header (24) to the load via the pipe (28). In the multi-tube once-through boiler (21), the combustion / stop control of the gas burner mechanism (27) is performed in relation to the supply of water into the water pipe and the load utilization amount. Therefore, in the multi-tube once-through boiler (21) of this type, the amount of water supplied to the water pipe (25) by the water supply pump (26) and the amount of load utilization, that is, the control of the water level in the water pipe can be performed. It is emphasized.
Conventionally, a double water level control system is known in relation to the control of the water level in a water pipe. The dual water level control system includes a boiler body (22) for the boiler body (22).
Water level control tube (29) communicating with the water pipe (25) on the outside of 2)
And a water level detector (30) for directly detecting the water level in the water pipe (25) in the upper header (24). The water level controller (29) is provided with, for example, three first, second and third electrode rods (31), (32) and (33) having different lower end heights from each other. Each water level is detected by contact with the water level liquid level in the water level control cylinder (29) communicating with the lower end and the boiler water pipe,
Output the ON signal. According to the example shown in the figure, when the water surface reaches the first electrode rod (31), a signal for turning off the water supply pump is output, and when the water surface cuts off the second electrode rod (32), the signal for turning on the water supply pump is output. When the water surface cuts off the third electrode rod (33), the water level is set to a low level, the gas burner mechanism (27) is cut, and a signal for activating the alarm buzzer is output. On the other hand, the water level detector (3
0) is the first end of the water level control cylinder (29)
The electrode rod (34) having a detection position higher than the electrode rod (31) of (3), and the water surface in the water pipe (25) is the electrode rod (3
When it reaches 4), it outputs a water pump OFF signal, and when the water surface cuts the electrode rod (34), it outputs a water pump ON signal. This dual water level control system has a water level control tube (29)
When the water level in the water reaches the first electrode rod (31) and the water level in the water pipe (25) reaches the electrode rod (34), the water supply pump (26) is stopped and the water level in the water level control cylinder (29) When the second electrode rod (32) cuts or the water level in the water pipe (25) cuts the electrode rod (34), the water supply pump (26) is activated. Normally, each of the above control timing,
The ON and OFF delay times are preset.
In the conventional device, the water level detector (30) is configured such that the water level in the water pipe (25) reaches the detection end of the electrode rod (34),
For example, an OFF delay time of about 15 seconds (a preset fixed value) was set, and the water supply pump (26) was turned off after the delay time had elapsed. However, as described above, if the water supply pump OFF delay time of the water level detector (30) is set to a constant value in advance, the actual water supply amount may change due to fluctuations in boiler internal pressure and deterioration of the water supply pump capacity. We cannot deal with such cases. For example, when the pressure inside the boiler is high, or when the capacity of the water supply pump decreases, the actual water supply amount also decreases, and the water surface comes to a position lower than usual. In this case, the water pipe tends to be overheated, which is not desirable. In consideration of the above points, if the water supply pump OFF delay time is set to the upper limit side (safety side), that is, if it is set for a long time, too much water will enter the water and the dryness will decrease, and if it is set to the lower limit side, it will prevent boiler protection. It doesn't make sense.

(C) Technical Problem of the Present Invention Therefore, in the present invention, in a system in which the water level in a water pipe is directly detected to control ON / OFF of a water supply pump, the advantage of dual water level control is applied as it is. Water pump OF
This is to solve the problem of keeping the F delay time constant, and it is possible to always detect the capacity of the water supply pump and change the water supply pump OFF delay time according to the capacity of the water supply pump. An object of the present invention is to provide a water supply control device in the dual water level control system.

(D) Technical Means of the Present Invention To achieve the above object, the present invention specifically connects the lower header (3) and the upper header (4) with a large number of water pipes (5). The water supply pump (6) communicating with the lower header (3) for the multi-tube once-through boiler (1)
And a first electrode rod (11) which is connected to the water pipe (5) through the lower header (3) and the upper header (4) and which detects the water level and outputs a water level signal inside. The water level control tube (9) and the upper header (4) have a detection position higher than the first electrode rod (11) and detect the water level in the water pipe (5). A water level detector (1 equipped with an electrode rod (14) that outputs a water level signal
0) and a double water level control system including a delay timer mechanism (16) for controlling the water supply pump (6) in response to the water level signal of the water level detector (10), the first electrode rod (11) ) Water level signal and the electrode rod (1
The controller (15) for stopping the water supply pump (6) after the water supply pump OFF delay time t has elapsed since the delay timer mechanism (16) was activated in response to the water level signal of 4), and the water supply in the water supply pump (6). Water supply capacity detection means for detecting the capacity, and the water supply pump OFF delay time t in the controller (15) can be variably and automatically adjusted according to the output signal from the water supply capacity detection means. Water pump OF that matches the capacity of water pump (6)
This is a water supply control device in a dual water level control system characterized in that the F delay time t is controlled and adjusted.

(E) Embodiment of the present invention Hereinafter, a water supply control device in a dual water level control system according to the present invention will be described in detail based on a specific embodiment shown in FIG.

As shown in FIG. 1, the multi-tube type once-through boiler device (1) is
It has a boiler body (2) in which an annular lower header (3) and an annular upper header (4) are connected by a number of water pipes (5). The lower header (3) of the boiler body (2) is connected to a water supply pump (6) so that water can be supplied into the water pipe (5). The water supplied into the water pipe is heated by the gas burner mechanism (7) and supplied as hot water or steam from the upper header (4) to the external load via the pipe (8). On the other hand, the double water level control system in the multi-tube once-through boiler (1) has a water level control tube (9) communicating with the water tube (5) outside the boiler body (2) with respect to the boiler body (2). And a water level detector (10) for directly detecting the water level in the water pipe (5) in the upper header (4). The water level control tube (9) has, for example, three first and second lower end heights.
And the third electrode rods (11), (12) and (13) are provided, and the respective water levels are changed by the contact between the lower end of each electrode rod and the water level surface of the water level control tube (9) communicating with the boiler water pipe. Detects and outputs an ON signal. According to the embodiment shown in FIG. 1, when the water surface reaches the first electrode rod (11), a signal for turning off the water feed pump is output, and when the water surface turns off the second electrode rod (12), the water feed pump is turned on. A signal is output, and when the water surface cuts the third electrode rod (13), a low water level is set, the gas burner mechanism (7) is cut, and a signal for activating an alarm buzzer is output. On the other hand, the water level detector (10) is composed of an electrode rod (14) having a lower end height higher than that of the first electrode rod (11) in the water level control tube (9), and the water pipe (5). When the water surface inside reaches the electrode rod (14), a signal of water feed pump OFF is output, and when the water surface cuts off the electrode rod (14), a signal of water feed pump ON is output. In the present invention, the output signal of the water level detector (10) is connected to the controller (15) including the delay timer mechanism (16). For example, in the example shown in the figure, when the water surface in the water pipe (5) reaches the electrode rod (14) in the water level detector (10), the detection signal is input to the controller (15) and the delay timer is set. An OFF signal is output to the water supply pump (6) via the mechanism (16). The delay timer mechanism (16) includes a timer (17) which operates by receiving the output of the water level detector (10) and a timer contact (18) provided in a power supply circuit of the water supply pump (6). ing.
In this double water level control system, the water level in the water level control cylinder (9) reaches the first electrode rod (11), and the water level in the water pipe (5) reaches the electrode rod (14) so that the delay timer mechanism ( The controller (15) stops the water supply pump (6) after the water supply pump OFF delay time t elapses after the operation of (16), and the water level in the water level control tube (9) cuts off the second electrode rod (12). Alternatively, when the water level in the water pipe (5) cuts the electrode rod (14), the controller (1
5) activates the water supply pump (6).
In the feature of the present invention, the timer (17) in the delay timer mechanism (16) is controlled by means for detecting the capacity of the water supply pump (6). In one example, the means for detecting the capacity of the water supply pump (6) measures a flow rate per unit time by a flow meter (19) connected to the water supply pump (6), and a timer is based on the measured value. This is a method to set the daytime in (17). In another example, the means for detecting the capacity of the water supply pump (6) is configured so that the ON time of the water supply pump (6) (for example, the first electrode rod (11) in the water level control cylinder (9)) under a constant pressure. The water surface displacement time with the second electrode rod (12) is measured, and the timer (17) is based on the measured value.
This is a method to set the daylight time in. According to the present invention, the water supply pump capacity during the operation of the boiler device is detected by the above configuration, and the water supply pump OFF delay time is automatically controlled according to the capacity of the water supply pump to detect the water level in the water level detector. After that, the water supply pump can be stopped after the water supply pump OFF delay time has elapsed.

(F) Effects of the present invention The water supply control device in the dual water level control system having the above-described configuration is a dual water level control system in which the water level in the water pipe is directly detected to control the ON / OFF of the water supply pump. Providing detection means to detect the water supply capacity of the pump,
By adjusting the delay time t of the controller according to the output signal from the detecting means,
OFF corresponding to the capacity of the feed pump during boiler operation
It is possible to set the delay time, prevent a decrease in dryness due to too much water entering the water pipe, and have an appropriate water level width in terms of boiler protection.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a concrete embodiment of a water supply control device in a dual water level control system according to the present invention, and FIG. 2 is a conventional dual water level control type multi-tube once-through boiler device. It is a schematic explanatory drawing shown. (1) …… Multi-tube type once-through boiler (2) …… Boiler body (3) …… Lower header (4) …… Upper header (5) …… Water pipe (6) …… Water supply pump (9) …… Water level Control tube (10) …… water level detector (11), (12), (13), (14) …… electrode rod (15) …… controller (16) …… delay timer mechanism (19) …… flow rate Total

Claims (1)

[Claims] 1. A lower header (3) and an upper header (4)
For a multi-tube once-through boiler (1) in which a plurality of water pipes (5) communicate with each other, a water supply pump (6) communicating with a lower header (3), a lower header (3) and an upper header (4)
The first electrode rod (1 which is connected to the water pipe (5) through the
Water level control tube (9) with 1) and upper header (4)
And an electrode rod (14) which has a detection position higher than the first electrode rod (11) and which detects the water level in the water pipe (5) and outputs a water level signal. A double water level control system including a water level detector (10), including a delay timer mechanism (16) for receiving a water level signal from the water level detector (10) and controlling the water supply pump (6), Receives the water level signal from the electrode rod (11) of the
The controller (15) for stopping the water supply pump (6) after the water supply pump OFF delay time t has elapsed since the delay timer mechanism (16) was activated in response to the water level signal of 4), and the water supply in the water supply pump (6). Water supply capacity detection means for detecting the capacity, and the water supply pump OFF delay time t in the controller (15) can be variably and automatically adjusted according to the output signal from the water supply capacity detection means. Water pump OF that matches the capacity of water pump (6)
A water supply controller in a dual water level control system, characterized in that the F delay time t is controlled and adjusted.