JP6719770B2 - All blow implementation boiler - Google Patents

Description

The present invention, in order to discharge the sludge and the like generated in the water pipe of the boiler, to carry out all the blow to discharge all boiler water from the boiler bottom regularly, blow water discharged from the boiler to the neutralization device. The present invention relates to an all-blowing boiler, which is designed to be discharged out of the system after being neutralized.

In a boiler that heats water to generate steam, the boiler water is adjusted to a high alkali with a pH of 11.0 to 11.8 by injecting chemicals to prevent corrosion in the water pipe that is in contact with the boiler water. doing. In a steam boiler, the boiler water is concentrated due to the generation of steam, so the boiler water that has been concentrated at a fixed rate relative to the supplied water is discharged, and instead, unconcentrated water is supplied into the boiler to improve the water quality. Concentrated blow to keep Further, since the dissolved solids in the boiler water are concentrated and sludge and the like are accumulated on the bottom of the boiler when the boiler is operated for a long time, all the blowout of discharging all the boiler water from the bottom of the can is regularly performed.

All blows are performed when the combustion time of the boiler and the like are integrated and the integrated value reaches a predetermined value. Since the boiler water is highly alkaline as described above, if there is a drainage regulation, a neutralization device should be installed to neutralize blow water as described in JP 2012-251685 A. Is also widely practiced. A neutralizer that mixes carbon dioxide gas from a cylinder and blow water to neutralize blow water is used, but the heat resistance temperature of the neutralizer is lower than that of the boiler, so When blown water enters the neutralization device, it may be deteriorated by heat or deteriorated in performance.

In the invention described in JP 2012-251685 A, the blow water is stored in a blow water tank, and the feed water is cooled by sending the blow water in the blow water tank to a feed water preheater that exchanges heat with the boiler feed water. The process and the cooling water cooling process by supplying the cooling water to the blow water tank are performed.

In the case of concentrated blow, the temperature of concentrated blow water becomes a problem because the temperature of concentrated blow water decreases as soon as it is discharged to the outside of the boiler, because the frequency of discharge is small but the amount of discharged water once is small. It doesn't happen very often. However, in the case of full blow, the frequency of implementation is low, but the amount of wastewater discharged once is large, so the cooling of the full blow water after discharge from the boiler is not in time, and there is a high possibility that high temperature blow water will be sent to the neutralization device. Become. When the amount of cooling water supplied to the blow water tank is increased as in the invention described in JP 2012-251685 A, a large amount of all blow water can be cooled, but in that case, the blow water tank is large. It was necessary to increase the capacity, and the size of the device was increased, and the cost of the device was also increased. In addition, this cooling water is discarded together with the blow water, and the amount of water used increases as the amount of cooling water increases.

JP 2012-251685 A

The problem to be solved by the present invention is to provide a full-blowing boiler capable of preventing the blow-up water tank from becoming large in size while preventing all high-temperature blow water from being sent to the neutralizer.

In the invention according to claim 1, all blow valves are installed in all blow pipes connected to the bottom of the boiler, and all blow valves are opened to discharge boiler water from the boiler. In the case of full blow, open control is performed to open all blow valves for a short time to discharge all blow water, and close control to close the blow valves for a time longer than the open control time to interrupt discharge of all blow water. Alternately, the intermittent drainage is repeated a plurality of times, and after the intermittent drainage is performed, continuous drainage is performed in which all blow valves are kept open.

The invention according to claim 2 has a water level detection device for detecting the water level at the water supply start water level and the water supply stop water level in the boiler in the full blow implementation boiler of the previous term, and water supply is performed when the water level in the boiler drops to the water supply start water level. Is started, and when the water supply is stopped when it rises to the water supply stop water level, all blows are started after detecting that the water level in the boiler has dropped to the water supply start water level. ..

By carrying out the present invention, in the entire blowing process of the previous period for draining high-temperature boiler water, it is possible to enhance the effect of lowering the temperature due to heat dissipation by intermittently discharging all the blowing water. It is possible to reduce the influence of the heat of. Further, in the latter full blow process in which the pressure in the boiler and the boiler water temperature are decreasing, the sludge discharge effect can be increased by continuously discharging all the blow water. By switching between intermittent drainage and continuous drainage, it is possible to achieve both protection of the neutralization device and drainage of sludge without installing a large capacity blow water tank.

Flow diagram of a boiler implementing the invention Time chart of the entire blow process in the boiler implementing the present invention Flow diagram of a boiler implementing the present invention with multiple cans installed

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flow chart of a boiler embodying the present invention, FIG. 2 is a time chart at the time of all blow steps in a boiler embodying the present invention, and FIG. 3 is a multi-can of a boiler embodying the present invention. It is a flow chart in installation.

The boiler 1 heats the boiler water by burning to generate steam, and takes out the steam from the upper portion of the boiler. The boiler is connected to a water supply pipe 6 at the bottom, and water is supplied from the bottom of the boiler. Water is supplied to the boiler through a water supply pipe 6 in which a water supply pump 13 is installed, and the water supply to the boiler is controlled based on the water level in the boiler. A water level detection device 12 for detecting the water level in the boiler is installed in advance, and the water level detection device 12 detects the presence or absence of water at the water supply start water level (E2 water level) and the water supply stop water level (E1 water level). When the water level in the boiler is lower than the water supply start water level, the operation of the water supply pump 13 is started to supply water to the boiler, and when the water level in the boiler rises to the water supply stop water level or higher, the water supply pump 13 is activated. Stop and stop supplying water to the boiler.

In the boiler, boiler chemicals for preventing corrosion in the water pipe section are supplied, and a chemical injection pump 4 for injecting the chemicals into the water supply pipe 6 on the downstream side of the water supply pump 13 is installed. The chemical injection pump 4 injects a chemical at a constant rate according to the amount of water supplied.

A combustion chamber is installed in the central portion of the boiler 1, and a combustion device 7 that combusts toward the combustion chamber is installed above the boiler 1. In the boiler 1, the boiler water in the boiler is heated by the heat generated in the combustion device 7. When the boiler water is heated, it boils in the boiler, steam is generated, and boiling of the boiler water occurs. A steam-water separator 8 for separating boiler water and steam is installed in the boiler, the boiling water and steam are separated by the steam-water separator 8, and the separated steam is taken out from the upper part, and the remaining boiler Water is returned to the bottom inside the boiler.

Since this boiler supplies water from one side and takes out only steam from the other side, impurities contained in the boiler feed water are concentrated inside the boiler. Therefore, concentrated blow is carried out to prevent the boiler water from over-concentrating, and the total blow to discharge the sludge accumulated at the bottom of the can by concentrating the dissolved solids contained in the boiler water. I do.

Since the most concentrated boiler water is the boiler water separated by the steam separator, the steam blower 9 is connected to the steam separator 8, and the concentrate blow valve 9 is installed in the steam blower 9. Keep it. The boiler water concentration is calculated using a sensor that detects the quality of the boiler water, and the boiler water concentration is calculated by calculating from the boiler feed water quality and water supply amount, and the concentration is maintained to maintain a certain degree of concentration. Perform blow. When performing the concentrated blow, the concentrated blow valve 3 is opened, and the concentrated blow water is discharged through the concentrated blow pipe 9.

All blows are discharged from the bottom of the boiler can. The entire blow pipe 10 for discharging sludge from the bottom of the can is connected to the bottom of the boiler 1, and the entire blow valve 2 is installed in the middle of the entire blow pipe 10. When all blow valves 2 are opened, boiler water is discharged through all blow pipes 10.

Boiler water is adjusted to be highly alkaline by injecting chemicals, so it is necessary to neutralize when it is necessary to comply with drainage regulations. In that case, a neutralization device 5 is installed. .. As the neutralizer 5, there is known a neutralizer which mixes carbon dioxide gas supplied from a carbon dioxide gas cylinder and alkaline blow water with a mixer. The concentrated blow pipe 9 and all blow pipes 10 are connected to the neutralization device 5, and the concentrated blow water from the concentrated blow pipe 9 and all blow water from all blow pipes 10 are sent to the neutralizer 5. Keep it.

Operation control of the boiler is performed by the operation control device 11. The operation control device 11 is connected to the water level detection device 12, the water supply pump 13, the chemical injection pump 4, the concentrated water blow valve 3, the full blow valve 2, the combustion device 7, etc., and operates the respective blow valve 2 and other devices. Control. Concentration blow is carried out while burning in the boiler, but in the case of full blow to discharge all boiler water, it cannot be done without stopping the combustion operation of the boiler, so generally after one day of operation Such as when the driving is no longer necessary.

Moreover, as shown in FIG. 3, when multiple boilers are installed in which multiple boilers are installed in parallel and a spare can that does not require combustion is installed, the total blow time is reached. Alternatively, all the blows may be performed immediately by removing the boiler from the target of the unit number control. In the case of FIG. 3, three boilers 1 and a unit number controller 14 that outputs a combustion command to each boiler are installed, and the unit number controller 14 is a steam header that collects the steam generated in each boiler. The combustion amount of each boiler is determined based on the steam pressure value, and a combustion command for the required combustion amount is output to each boiler. In this case, if there are two boilers that are subject to unit control, and one is a spare can that is removed from the unit control target boiler, the boiler that has reached the full blow time is removed from the unit control target and used as a spare can. , Combustion operation is performed with the boiler that had been a spare can until then as the boiler for which unit number is controlled. By doing this, the boiler, which has reached the time of full blow, can immediately perform full blow.

The heat resistant temperature of the neutralizer 5 is lower than that of the boiler, and when blow water is sent to the neutralizer 5 as it is, the heat resistant temperature of the neutralizer 5 may be exceeded. In the case of the concentrated blow, since the amount of concentrated blow water discharged at one time is small, the temperature of the blow water is lowered due to heat dissipation during the process, and the heat of the blow water rarely adversely affects the neutralization device. However, in the case of full blow, since the amount of water discharged is large, the amount of temperature decrease due to heat radiation is relatively small, and high-temperature blow water is sent to the neutralizer 5 as it is for neutralization. The device 5 may be deteriorated or its performance may be deteriorated.

Therefore, in the operation control device 11, the entire blowing process is divided into the first term and the second term. In the full blow process in the first half, all the blow valves 2 are repeatedly opened for a short time and closed for a longer time than the open time. For example, all blow valves 2 are opened for 10 seconds and intermittently opened and closed for 10 minutes so that they are alternately repeated 5 times. Then, after intermittently opening and closing all blow valves 2, control is performed to continuously open all blow valves.

The control at the time of full blow will be described based on FIG. In Fig. 2, when combustion was performed in the boiler for which the number of units is controlled, the combustion time after the previous total blow reached the set value for performing all blows. Is to be carried out.

In this boiler, when normal combustion is performed, when the water level inside the boiler falls to the water supply start water level, the water supply pump 13 is operated to raise the water level, and when it rises to the water supply stop water level, the operation of the water supply pump 13 is stopped. doing. The operation control device 11 measures the integrated value of the combustion time after the last full blow, and when the integrated value reaches the set value for the full blow execution, outputs that the full blow time has come. Upon receiving the all blow timing signal from the operation control device 11, the number control device 14 removes the boiler from the number control target and causes all blows.

In the all-blowing process, a first-stage process in which short-time opening and long-time closing of all the blow valves 2 are repeated and a second-stage process in which they are continuously opened are performed. When all the blow valves 2 are opened, a small amount of water is discharged for a short time, and the water level in the boiler is reduced by the amount of water discharged. When all the blow valves 2 are closed, the water level in the boiler does not decrease, so the water level decreases stepwise.

Immediately after starting all blows, the pressure inside the boiler is high and the boiler water temperature is also high, so high temperature blow water is discharged in the previous full blow. However, if the blow water is not discharged continuously but at intervals and intermittently so that the blow water is discharged little by little, the temperature of the discharged blow water is high, but it is discharged once. Since the amount of blown water is small, the temperature drop of the blown water due to heat radiation from the blown water is large. Therefore, the temperature of the blow water sent to the neutralization device 5 becomes low, and the influence of heat on the neutralization device 5 can be reduced. Further, if the total amount of blow water is small, the temperature of the blow water can be lowered by simply mixing a small amount of cooling water.

In the first stage process of all blows, intermittent drainage is performed by opening and closing all blow valves 2, but in the latter stage process to be performed thereafter, continuous drainage is performed by keeping all blow valves 2 open.

In the first half of the full blow, if the water is discharged intermittently, the amount of boiler water accumulated in the boiler will decrease, and the pressure inside the boiler and the temperature of the boiler water will decrease. After the boiler water temperature has dropped to some extent, the influence of heat on the neutralization device 5 can be suppressed even if all blows are continuously performed. Further, if the pressure inside the boiler is reduced by performing the full blow, the jet pressure when the full blow valve 2 is opened will be reduced. When the jet pressure became smaller, the discharge effect of sludge in the boiler was lessened with the finely cut drainage by intermittently opening and closing all blow valves 2. However, continuous drainage should be performed. Can discharge more sludge.

When all the boiler water in the boiler is discharged, the operation control device 11 closes all blow valves 2 and operates the water supply pump 13 to perform initial water supply. The initial water supply is performed until the water level in the boiler reaches the water supply stop water level.

Further, the boiler of the embodiment starts water supply when the water level drops to the water supply start water level, and stops water supply when the water level rises to the water supply stop water level, so the water level in normal times is the water supply start water level and the water supply stop water level. It goes up and down between. Therefore, the implementation of all blows should be set to start when the water level in the boiler has dropped to the water supply start water. In the case of full blow that discharges all boiler water, it is possible to reduce the amount of wastewater during full blow by performing it after the water level has dropped to the water supply start water level, rather than performing full blow when the water level inside the boiler is high. ..

It should be noted that the present invention is not limited to the embodiments described above, and many modifications can be made by a person having ordinary skill in the art within the technical idea of the present invention.

1 boiler
2 All blow valves
3 Concentrated water blow valve 4 Chemical injection pump 5 Neutralizer 6 Water supply pipe 7 Combustion device 8 Steam separator 9 Concentrated blow pipe 10 All blow pipe 11 Operation control device 12 Water level detection device 13 Water supply pump 14 Unit control device

Claims (2)

When all blow valves are installed in all blow pipes connected to the bottom of the boiler, and all blow valves are opened to discharge boiler water from the boiler, when performing all blow operations, Intermittent drainage in which the open control for opening all blow valves for a short time to discharge all blow water and the closed control for closing the blow valves for a time longer than the open control time to interrupt the discharge of all blow water are repeated multiple times alternately The all-blow-execution boiler is characterized in that continuous discharge is carried out by maintaining all the blow valves open after the intermittent discharge. The all-blowing boiler according to claim 1, further comprising a water level detection device that detects a water level at a water supply start water level and a water supply stop water level in the boiler, and starts water supply when the water level in the boiler drops to a water supply start water level, and then supplies water. The all-blowing boiler, wherein when the water supply is stopped when the water level rises to the stop water level, all blows are started after detecting that the water level inside the boiler has dropped to the water supply start water level.

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