JP4294564B2 - Soot blower control device - Google Patents

Description

  The present invention relates to a technique related to execution control of piping warming in a soot blower facility.

  The soot blower equipment generally includes a soot blower group that sequentially branches in a pipe through which superheated steam flows, a temperature detector that detects the temperature of pipes or fluids downstream from the soot blower group, and a downstream warming device. And a valve. In such a soot blower facility, referring to FIG. 1 showing a basic system configuration of the soot blower facility, when trying to operate any of the soot blowers 11 to 14 in the soot blower group, the pipe 2 or the pipe internal fluid is drained or If it is wet steam, the drain blow attack will damage the equipment subject to the soot blower. Therefore, this temperature is set on the precondition that the temperature of the pipe 2 or the pipe internal fluid is slightly higher than the saturation temperature. If not, the warming valve 4 is opened in advance before the soot blower is operated, and the flow of steam (or fluid) from the soot blower steam source 1 to the warming drain discharge destination 5 through the pipe 2 is secured. Then, the piping 2 is heated by the heat of the steam, and the warming is performed so that the fluid inside the piping becomes an overheated region. To implement.

  The completion of the warming is known when the temperature detected by the temperature detector 3 installed on the downstream side of the pipe 2 reaches a specified value that is slightly higher than the saturation temperature. Then, the soot blowers 11 to 14 are operated.

  FIG. 3 shows a system warming start logic circuit in the prior art. In FIG. 3, in accordance with the order in which the soot blowers 11 to 14 branch from the upstream side to the downstream side of the pipe 2, NO. 1, NO. 2, ... NO. n-1, NO. n, and soot blower numbers. In FIG. 1 soot blower operation command, 32 is NO. 2 soot blower operation command, 33 is NO. n-1 soot blower operation command, 34 is NO. n soot blower operation command, 35 is a system temperature specified value or more, 36 is a logical sum element, 37 is a logical product element, 38 is a negative element, and 39 is a system warming start command.

  As can be seen from the system warming logic control circuit shown in FIG. 3, when any one of the soot blowers operates as a soot blower and the system temperature does not reach a specified value (during the operation of any one soot blower, the temperature detector 3 Since there is no flow of fluid in the place where the pipe is installed, the temperature gradually decreases due to heat radiation from the pipe 2, and the condition of the system temperature not lower than the system temperature regulation value 35 is not achieved), and the output from the negative element 38 is When this is turned on and the output from the logical product element 36 is turned on by the soot blower operation command, the warming start command 39 is issued before the next soot blower is operated by the output from the logical product element 37 to operate the warming. It becomes. If the temperature detector 3 is equal to or higher than the system temperature predetermined value 35, the output of the negative element 38 is turned off, so that the warming start command 39 is not issued and the soot blower is operated sequentially.

Moreover, as a prior art aiming at reducing the heat loss due to warming of the soot blower, for example, there is one described in Patent Document 1. According to Patent Document 1, the soot blower valve is closed when the steam temperature reaches a warming end temperature higher than the saturation temperature of the steam pressure, and the warming valve is closed when the steam temperature reaches the saturation temperature of the steam pressure. By making it open, it does not frequently warm.
Japanese Patent Laid-Open No. 9-60852

  However, according to the conventional system warming logic control circuit shown in FIG. 3, when the temperature detector does not reach the system temperature predetermined value or more, the logic of the next soot blower operation command (any one command of 31 to 34) is obtained. The warming start command 39 is issued by the product 37 and the warming is performed. However, depending on the upstream / downstream relationship on the piping between the soot blower of the previous operation and the soot blower of the current operation, the warming may not be necessarily required. Because of this (the reason will be described later), there is a problem that steam is wasted and the soot blower operation timing is delayed.

Further, Patent Document 1 described above, but are intended to reduce heat loss, and performs devised against the apparatus itself for performing the warming.

  The objective of this invention is providing the soot blower control apparatus which can manage appropriately the necessity of warming implementation, and can reduce the opportunity of unnecessary warming.

In order to solve the above problems, the present invention mainly adopts the following configuration.
A plurality of soot blowers that sequentially branch from the upstream side to the downstream side of the pipe through which the fluid flows, a temperature detector that detects the temperature of the pipe or the fluid in the pipe downstream of the plurality of soot blowers, and a further downstream warming A soot blower control device that performs execution control of the warming based on a detected temperature from the temperature detector,
Even if the temperature of the pipe or the fluid in the pipe detected by the temperature detector falls below a specified value that can be drained of the fluid, the soot blower to be operated this time is the same soot blower as the soot blower that was operated last time, Or when it is a soot blower branched on the upstream side with respect to the soot blower operated last time, it is set as the structure which controls so that the warming of the said piping is not implemented.

  According to the present invention, unnecessary warming can be avoided, and the frequency of wasteful use of steam and delay in the operation timing of the soot blower can be reduced.

  A soot blower control device according to an embodiment of the present invention will be described in detail below with reference to FIGS. 1 and 2. FIG. 1 is a basic system diagram showing a soot blower equipment to which a soot blower control device according to an embodiment of the present invention is applied. FIG. 2 is a diagram showing a system warming start logic circuit in the soot blower control apparatus according to the embodiment of the present invention.

  First, the outline of the soot blower control device according to the embodiment of the present invention will be described with reference to FIG. In FIG. 1, 1 is a soot blower steam source, 2 is piping, 3 is a temperature detector, 4 is a valve, 5 is a warming drain discharge destination, 11 is NO. 1 soot blower, 12 NO. 2 soot blower, 13 NO. n-1 soot blower, 14 is NO. n soot blower. Assuming that the temperature of the pipe 2 or the fluid inside the pipe is slightly higher than the saturation temperature, that is, the system temperature is not less than the predetermined value, if this temperature is not reached, warming is performed in advance before operating the soot blower. The valve 4 is opened, the flow of superheated steam (or fluid) from the soot blower steam source 1 through the pipe 2 to the warming drain discharge destination 5 is secured, the pipe 2 is heated by the heat of the steam, and the fluid inside the pipe Warming is performed so that is in the overheated area.

  Here, the necessity of warming is described. (1) If the branch position of the soot blower operated this time from the pipe 2 is downstream with respect to the soot blower operated last time, there is no fluid flow and heat is radiated from the pipe 2. It is expected that the internal fluid is drained due to cooling, and warming is necessary.

  Further, (2) if the branch position is reverse, that is, if the soot blower operating this time is upstream relative to the last operated soot blower, the branch point is on the path for supplying steam to the previously operated soot blower. Therefore, for the soot blower operating this time, the steam path was always warmed up, and it may be considered that there is no draining of the internal fluid until a certain time has elapsed since the completion of the operation of the soot blower operated last time, No warming is required.

  In the prior art, by the system warming start logic circuit shown in FIG. 3, in any of the cases (1) and (2), the temperature detector is equal to or higher than the system temperature default value. If not, warming is performed. Therefore, in the case of (2), although warming is not necessary, the warming is performed by wasting steam, and the warming is performed prior to the soot blower, so that the timing of the soot blower operation is delayed.

  Therefore, in the soot blower control device according to the embodiment of the present invention, in the case of (2) described above, that is, when the branch position of the soot blower that is currently operated with respect to the soot blower that was previously operated is the upstream side, The soot blower is operated without performing warming until a predetermined time has elapsed from the completion time point. Specifically, the soot blower that operated last time is NO. 2, the soot blower operating this time is NO. 3 corresponds to the case of (1) above, and the soot blower operated last time is NO. 3, the soot blower operating this time is NO. If it is 2, it corresponds to the case of (2) above. However, in this case of (2), even if the system temperature exceeds the predetermined value, it has not been reached until a certain time has passed since the last operation of the soot blower operated. The soot blower is operated without warming. At this time, even if the branch position of the soot blower operating this time is upstream, it is assumed that cooling of the pipe 2 has progressed after a certain period of time has elapsed since the completion of the soot blower operation that was operated last time, and warming is performed. carry out. This fixed time is determined in consideration of the time until the pipe once warmed down to the saturation temperature of the fluid.

  FIG. 2 shows a system warming start logic circuit in the present embodiment. Here, 31 is NO. 1 soot blower operation command, 32 is NO. 2 soot blower operation command, 33 is NO. n-1 soot blower operation command, 34 is NO. n soot blower operation command, 35 is more than the system temperature specified value, 36, 45, 49, 53 are logical sum elements, 37, 48, 52, 56, 60 are logical product elements, 38, 47, 51, 55, 59 are negative Element 39, system warming start command, 41 NO. During 1 soot blower operation, 42 is NO. During 2 soot blower operation, 43 is NO. During operation of the n-1 soot blower, 44 is NO. During the n soot blower operation, 46, 50, 54, and 58 denote delay recovery timers, respectively.

  In FIG. 2, the logic control (logic) for judging whether or not a certain time has passed since any of the soot blowers branching off from the pipe 2 on the downstream side of the soot blower including itself is operated. As an element. That is, in the soot blower system having the configuration shown in FIG. 1, each soot blower performs the necessity calculation of the necessity of warming as shown below.

  NO. As for 1 soot blower, {NO. 1, NO. 2, NO. n-1, NO. n during operation of one of the soot blowers (computed by the OR elements 53, 49 and 45) + the output of the delay recovery timer 46} via the negation element 47, the NO. The logical product with the 1 soot blower operation command 31 is calculated (calculated by the logical product element 48). The determination result of the necessity of warming as one soot blower is obtained. At this time, a logical product is taken with the fact that the system temperature not less than the predetermined value 35 has not been reached. It should be noted that if a certain period of time has elapsed since the completion of the operation of the soot blower operated last time by the delay recovery timer 46, the output of the negating element 47 is turned on and becomes one element of the warming start.

  NO. As for 2 soot blowers, {NO. 2, NO. n-1, NO. n during operation of one of the soot blowers (calculated by the OR elements 53 and 49) + delay return timer 50} output from the negation element 51, the NO. A logical product with the 2-soot blower operation command 32 is calculated (calculated by the logical product element 52), and the NO. The determination result of the necessity of warming as a 2 soot blower is obtained.

  NO. As for n-1 soot blower, {NO. n-1, NO. n during operation of one of the soot blowers (calculated by the logical sum element 53) + the output of the delay recovery timer 54} through the negation element 55, the NO. The logical product with the n-1 soot blower operation command 33 is calculated (calculated by the logical product element 56), and the NO. The determination result of the necessity of warming as an n-1 soot blower is obtained.

  NO. n soot blower, {NO. n soot blower in operation + delay return timer 58} output from the negation element 59 and the NO. n AND with the soot blower operation command 34 (calculated by the AND element 60), the NO. It is used to obtain the judgment result of the necessity of warming as an n soot blower.

  The NO. 1, NO. 2, NO. n-1, NO. One of the determination results of the necessity of warming as an n soot blower is established (calculated by the logical sum element 36) and detected by the temperature detector 3 of the pipe 2 or the pipe internal fluid installed on the most downstream side. If the system temperature is not more than the specified system temperature 35, the system warming corresponding to the branch position of the soot blower in (2) described above can be performed by using the logic control (logic) to issue the system warming start command 39. it can.

  As a result, in the embodiment of the present invention, it is possible to appropriately reduce the necessity of warming and to reduce heat loss by an approach of reducing unnecessary warming opportunities. That is, the waste of steam can be eliminated and the timing delay of the soot blower operation can be reduced.

  As described above, in the embodiment of the present invention, a plurality of soot blowers sequentially branch from a pipe from the upstream side to the downstream side of the pipe, and measure the temperature of the pipe or the fluid inside the pipe on the downstream side of the pipe. When the pipe or pipe internal fluid temperature detected by the temperature detector is below the specified value before operating the soot blower, the valve is opened and the pipe warming valve is installed. In the soot blower control device that controls the soot blower to operate after the temperature of the pipe or the pipe internal fluid detected by the temperature detector becomes equal to or higher than a specified value, before operating the soot blower, the temperature of the pipe or pipe internal fluid Is less than a specified value (for example, a temperature slightly higher than the saturation temperature), the soot blower operated this time is If the soot blower that was operated last time is a branch from the upstream side of the pipe with respect to the soot blower that was operated last time, the soot blower that was previously operated should not be warmed until a certain time has elapsed after the operation. It is characterized by performing a simple control.

It is a distribution diagram showing soot blower equipment to which a soot blower control device concerning an embodiment of the present invention is applied. It is a figure which shows the start logic circuit of the system warming in the soot blower control apparatus which concerns on embodiment of this invention. It is a figure which shows the start logic circuit of the system warming in a prior art.

Explanation of symbols

1 Soot blower steam source 2 Piping 3 Temperature detector 4 Valve 5 Warming drain discharge destination 11 NO. 1 soot blower 12 NO. 2 soot blower 13 NO. n-1 soot blower 14 NO. n Soot blower 31 NO. 1 soot blower operation command 32 NO. 2 Soot blower operation command 33 NO. n-1 soot blower operation command 34 NO. n soot blower operation command 35 system temperature specified value or more 36, 45, 49, 53 logical sum element 37, 48, 52, 56, 60 logical product element 38, 47, 51, 55, 59 negative element 39 system warming start command 41 NO. During 1 soot blower operation 42 NO. During 2 soot blower operation 43 NO. n-1 soot blower in operation 44 NO. n soot blower in operation 46, 50, 54, 58 Delayed recovery timer

Claims (2)

A plurality of soot blowers that sequentially branch from the upstream side to the downstream side of the pipe through which the fluid flows, a temperature detector that detects the temperature of the pipe or the fluid in the pipe downstream of the plurality of soot blowers, and a further downstream warming A soot blower control device that performs execution control of the warming based on a detected temperature from the temperature detector,
Even if the temperature of the pipe or the fluid in the pipe detected by the temperature detector falls below a specified value that can be drained of the fluid, the soot blower to be operated this time is the same soot blower as the soot blower that was operated last time, Alternatively, in the case of a soot blower that branches upstream from the soot blower that operated last time, the soot blower control device is controlled so as not to warm the pipe. In claim 1,
The soot blower control device is characterized in that, as a control condition for not performing the warming of the pipe, that it is within a certain time after the operation of the soot blower operated last time.

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