JPH087239Y2 - Boiler combustion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a combustion control device applied to control of a combustion system in a small boiler or the like.

[Prior Art and Problems Thereof] As is well known, the boiler device is generally subjected to ON-OFF combustion control operation according to the amount of steam used during its operation. In order to perform this ON-OFF combustion control operation safely and reliably, it is necessary to sufficiently exhaust combustible residual gas in the boiler furnace during the combustion stage. For that purpose, in conventional combustion control in a boiler system, a purging process is performed before and after the combustion stage. That is, in the conventional combustion control, as shown in FIG. 3, the combustion system of the boiler is cycled by the stages of pre-purge, ignition trial, combustion, and post-purge. In the conventional combustion control described above, even if there is a combustion request from the combustion request detector during or after the post-purge, the actual combustion is started from that point through the pre-purge stage. Therefore, there is a drawback that a time delay is caused by a pre-purge amount between the time when a combustion request is made and the time when combustion is started, the pressure in the boiler can is lowered during the pre-purge period, and a delay occurs in following the load. Was there. Furthermore, the conventional combustion control described above has a problem that the supply steam pressure sharply decreases due to a delay in load follow-up, particularly in a small boiler apparatus having a small amount of steam and water, which causes a trouble on the load side. Was there.

[Object of the Invention] This invention detects the combustion request or non-combustion request of the boiler by the combustion request detector provided in the boiler main body,
When controlling the combustion system of the boiler to the combustion stage or non-combustion stage, pre-purge, ignition try,
A combustion control device configured to be cycle-operated by the stages of combustion and post-purge, wherein after the post-purge in one combustion stage, when there is a next combustion request, it is possible to immediately shift to the next combustion stage, and It was made for the purpose of providing a material with a small heat loss.

[Configuration of the Invention] In order to achieve the above-mentioned object, the present invention specifically detects the combustion request or non-combustion request of the boiler by a combustion request detector provided in the boiler body, and determines the combustion system of the boiler. When controlling to the combustion stage or the non-combustion stage, in the combustion control device that operates the combustion system of the boiler by the stages of pre-purge, ignition try, combustion, and post-purge, the next combustion request is reached after the post-purge. During this period, a continuous purge stage for continuously purging the inside of the boiler furnace is set, and the air volume for purging the inside of the boiler furnace in the continuous purging is switched to a low air volume, and the boiler combustion system at the time of the next combustion request after the post-purge. Is a combustion control device for a boiler, which is provided with a control unit that immediately shifts to the combustion stage.

[Embodiment of the Present Invention] Hereinafter, a combustion control device for a boiler according to the present invention will be described in detail based on a specific embodiment shown in the drawings.

FIG. 1 shows an example of a boiler device to which the combustion control device of the present invention is applied. In the illustrated example, the boiler device has a combustion demand detector (2) attached to the boiler body (1). The combustion request detector (2) comprises, for example, a steam pressure detector or a temperature detector. On the other hand, the boiler device is provided with a combustion device (3). The combustion device (3) is connected to a blower (4) via a blower line (5). The combustion device (3) includes a low combustion fuel controller (6) for switching the combustion amount.
And a fuel controller (7) for high combustion. In the present invention, the combustion device (3) includes a combustion system constituted by one fuel controller which does not have the high combustion fuel controller (7). On the other hand, in the delivery line (5), there is provided an air volume switching controller (8) having a switching mechanism to obtain a low combustion air volume and a high combustion air volume commensurate with low combustion and high combustion. In the example shown, the control unit (9) is electrically connected to receive the output signal of the combustion request detector (2). The control unit (9), based on the combustion request signal from the combustion request detector (2), the low combustion fuel controller (6), the blower (4), the air volume switching controller (8) and ignition. Operate the device (10).

The boiler combustion control device according to the present invention operates as follows. Upon receiving the combustion request signal from the combustion request detector (2), the control unit (9) operates the blower (4) to blow the air corresponding to the high combustion into the boiler furnace to pre-purge (PR) the inside of the furnace. ) Do. After that, the ignition device (10) is operated, and at the same time, the combustion controller (6) is operated to perform an ignition try (IG). After the ignition trial, the ignition device (10) stops and shifts to the combustion (CO) stage. The combustion request detector (2)
When there is no more combustion request from the engine, the combustion controller (6) is closed to stop the combustion, and then the post-purging (PO) of only the air blow by the air blower (4) is performed. In this invention, after this post-purging (PO), continuous purging (C
P) stage is set. In the continuous purging (CP) stage, the air volume switching controller (8) provided in the air blowing line (5) is switched to the low air volume side by a signal from the control unit (9). In this way, post-purging (PO)
By continuously setting the continuous purge (CP), it is possible to immediately shift to the combustion stage (CO) by the ignition try without performing the pre-purge (PR) when the next combustion request is made.

[Advantages of the Invention] The combustion control device for a boiler of the present invention having the above-described configuration sets the continuous purge stage for continuously purging the inside of the boiler furnace after the post-purge, so that the next combustion request after the post-purge is requested. At times, it is possible to immediately shift to the combustion stage, the combustion delay due to the conventional pre-purge is eliminated, and the followability to the load can be improved. Further, the combustion control device for a boiler according to the present invention switches the air volume fed into the boiler furnace to a low air volume in the continuous purging, so that heat loss due to cooling of the boiler can can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an example of a combustion control device for a boiler according to the present invention, FIG. 2 is a time chart diagram showing an example of combustion control according to the present invention, and FIG. 3 is a conventional combustion control. It is a time chart figure which shows. (1) …… Boiler body (2) …… Combustion request detector (3) …… Combustion device (4) …… Blower (5) …… Blower line (6), (7) …… Fuel controller (8) ) …… Air volume switching controller (9) …… Control unit (10) …… Ignition device

Claims (1)

[Scope of utility model registration request] 1. A combustion request detector provided in a boiler body detects a combustion request or a non-combustion request of the boiler, and when the combustion system of the boiler is controlled to a combustion stage or a non-combustion stage, the combustion system of the boiler is pre-purged. In a combustion control device that is cycled by stages of ignition trial, combustion, and post-purge, after the post-purge, the stage of continuous purging that continuously purges the inside of the boiler furnace until the next combustion request is set. In the continuous purging, the air flow rate for purging the inside of the boiler furnace is switched to a low air flow rate, and a control unit is provided to immediately shift the combustion system of the boiler to the combustion stage when the next combustion is required after the post-purge. Boiler combustion control device.