Boiler system

Abstract

To provide a boiler system that inhibits a droplet condensation promoter from adhering to a boiler water pipe of a boiler and causing failure.SOLUTION: A boiler system 1 includes a boiler 70 and a heat exchanger 20. The boiler system 1 also includes a droplet condensation promoter treatment device 50 that is provided in at least one of a drain recovery line 122 and a boiler supply water line 132 to remove at least part of a droplet condensation promoter 140 included in at least one of drain water 120 flowing in the drain recovery line 122 and boiler supply water 130 flowing in the boiler supply water line 132.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a boiler system. [Background technology]

[0002] In a system in which steam is brought into contact with a cooling body in a heat exchanger to liquefy and condense, a boiler system is known in which a film-forming amine is injected into the steam header of the boiler as a method for promoting dropwise condensation and achieving efficient heat exchange. Patent Document 1 discloses a method for adding a dropwise condensation promoter to a boiler system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6506865 Summary of the Invention [Problem to be solved by the invention]

[0004] In a boiler system using a drop-type condensation promoter, excess drop-type condensation promoter that is not consumed in forming a film on the heat exchanger may be supplied to the boiler through drain recovery. In this case, the excess drop-type condensation promoter may be supplied to the boiler system, which may impair stable operation.

[0005] Therefore, an object of the present invention is to provide a boiler system in which the adhesion of droplets of condensation promoter to the boiler water tubes of the boiler and the resulting malfunction are suppressed. [Means for solving the problem]

[0006] The boiler system of the present invention is a boiler system comprising a boiler and a heat exchanger, and further comprising: a steam line having one end connected to the heat exchanger and flowing steam from the boiler to the heat exchanger; a drain recovery line having one end connected to the heat exchanger and flowing drain water generated by condensation of the steam in the heat exchanger; a recovery tank disposed at the other end of the drain recovery line and storing the drain water; a boiler feedwater line that flows the water stored in the recovery tank to the boiler as boiler feedwater; and a dropwise condensation accelerator that supplies a dropwise condensation accelerator to the steam line. The system further includes a promoter supply unit, a dropwise condensation promoter injection line having one end connected to the dropwise condensation promoter supply unit and the other end connected to the steam line, for injecting a dropwise condensation promoter from the dropwise condensation promoter supply unit into the steam line, and a dropwise condensation promoter treatment device provided in at least one of the drain recovery line and the boiler feedwater line, for removing at least a portion of the dropwise condensation promoter contained in at least one of the drain water flowing through the drain recovery line and the boiler feedwater flowing through the boiler feedwater line.

[0007] The method for controlling the injection of a dropwise condensation promoter of the present invention is a method for controlling the injection of a dropwise condensation promoter in a boiler system comprising a boiler and a heat exchanger, which monitors the temperature of a boiler water tube in the boiler, and when an abnormal rise in the temperature of the boiler water tube is detected, at least one of reducing the amount of the dropwise condensation promoter supplied and removing at least a portion of the supplied dropwise condensation promoter is carried out. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a boiler system in which the adhesion of droplets of condensation promoter to the boiler water tubes of the boiler and the resulting malfunction are suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a boiler system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a boiler system 1 of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing the boiler system 1 according to the embodiment of the present invention. The boiler system 1 includes a boiler section 10 in which one or more boilers 70 are installed, a heat exchanger 20, a steam line 112, and a steam line valve 114. One end of the steam line 112 is connected to the boiler section 10. The other end of the steam line 112 is connected to the heat exchanger 20. The steam line 112 allows steam 110 to flow from the boiler section 10 to the heat exchanger 20. The steam line valve 114 is provided in the steam line 112. The steam line valve 114 makes it possible to adjust the amount of steam 110 flowing through the steam line 112.

[0011] The boiler system 1 further includes a recovery tank 30 and a drain recovery line 122. One end of the drain recovery line 122 is connected to the heat exchanger 20. The other end of the drain recovery line 122 is connected to the recovery tank 30. Steam from the steam line 112 is condensed in the heat exchanger 20. The condensed steam becomes drain water 120. The drain recovery line 122 flows the drain water 120 from the heat exchanger 20 to the recovery tank 30.

[0012] The boiler system 1 further includes a boiler feedwater line 132. One end of the boiler feedwater line 132 is connected to the recovery tank 30. The other end of the boiler feedwater line 132 is connected to the boiler section 10. The boiler feedwater line 132 flows water stored in the recovery tank 30 from the recovery tank 30 to the boiler section 10. This water is called boiler feedwater.

[0013] The boiler system 1 further includes a raw water supply line 192, a water softener 194, and a deaerator 196. One end of the raw water supply line 192 is connected to the recovery tank 30. The raw water supply line 192 flows raw water 190 into the recovery tank 30. The water softener 194 and the deaerator 196 are provided on the raw water supply line 192 in this order from the upstream side to the downstream side.

[0014] The boiler system 1 further includes a dropwise condensation promoter supply unit 40, a dropwise condensation promoter injection line 142, and a dropwise condensation promoter injection device 144. One end of the dropwise condensation promoter injection line 142 is connected to the dropwise condensation promoter supply unit 40. The other end of the dropwise condensation promoter injection line 142 is connected to the steam line 112. The dropwise condensation promoter injection line 142 flows the dropwise condensation promoter 140 from the dropwise condensation promoter supply unit 40 to the steam line 112. The dropwise condensation promoter injection device 144 makes it possible to adjust the amount of the dropwise condensation promoter 140 flowing through the dropwise condensation promoter injection line 142. The dropwise condensation promoter 140 is an agent that changes the condensation form of steam on a heat exchanger to drops. An example of the dropwise condensation promoter 140 is a film-forming amine.

[0015] The boiler system 1 further includes a dropwise condensation promoter treatment device 50. The dropwise condensation promoter treatment device 50 is a device that removes at least a portion of the dropwise condensation promoter 140 contained in at least one of the drain water 120 and the boiler feed water 130. The dropwise condensation promoter treatment device 50 is provided in at least one of the drain recovery line 122 and the boiler feed water line 132. FIG. 1 shows an example in which the dropwise condensation promoter treatment device 50 is provided in the drain recovery line 122.

[0016] The boiler system 1 further includes a boiler chemical injection unit 60. The boiler chemical injection unit 60 is provided in the boiler feedwater line 132. The boiler chemical injection unit 60 injects boiler chemicals into the boiler feedwater 130 flowing through the boiler feedwater line 132. When the dropwise condensation promoter treatment device 50 is provided in the boiler feedwater line 132, the dropwise condensation promoter treatment device 50 is provided between the recovery tank 30 and the boiler chemical injection unit 60.

[0017] The boiler 70 is a device that generates steam by heating the supplied boiler feedwater 130. One or more boilers 70 are arranged in parallel in the boiler section 10. The boiler 70 is provided with a boiler water pipe 71, which is a member that heats the boiler feedwater 130, inside.

[0018] The boiler system 1 further includes a temperature monitoring unit 72. The temperature monitoring unit 72 is a part that monitors the temperature of the boiler water pipes 71. The temperature monitoring unit 72 is provided in the boiler water pipes 71. FIG. 1 shows an example in which one temperature monitoring unit 72 is provided for one boiler water pipe 71. One temperature monitoring unit 72 may be provided for each boiler water pipe 71.

[0019] The boiler system 1 further includes a supply amount adjustment unit 80. The supply amount adjustment unit 80 is a part that reduces the supply amount of the dropwise condensation promoter 140 when the temperature monitoring unit 72 detects an abnormal rise in the temperature of the boiler water pipe 71. The supply amount adjustment unit 80 is provided in the dropwise condensation promoter supply unit 40. The supply amount adjustment unit 80 adjusts the supply amount of the dropwise condensation promoter 140 by, for example, adjusting the dropwise condensation promoter injection device 144.

[0020] In the boiler system 1 of this embodiment, excess droplet-like condensation accelerator 140 adheres to the boiler water tubes 71 to form a water-repellent film, which can prevent the boiler water tubes 71 from overheating.

[0021] In a boiler system 1 in which steam from the boiler section 10 is brought into contact with a cooling body in a heat exchanger 20 to liquefy and condense, one method for promoting dropwise condensation and improving heat exchange efficiency is to inject a film-forming amine or the like into the steam line 112 as a dropwise condensation promoter 140. This technique increases the water repellency of the metal surface on the steam side of the heat exchanger 20, thereby preventing a decrease in heat exchange efficiency due to the formation of a water film. Dropwise condensation increases the heat exchange efficiency in heat exchange.

[0022] Furthermore, an energy saving technique for the boiler system 1 is to recover steam drain from the heat exchanger 20. By reusing the steam drain as boiler feed water, it is possible to reduce fuel consumption and save water.

[0023] In the boiler system 1 in which the dropwise condensation promoter 140 is injected into the steam line 112 and steam drain is recovered, the dropwise condensation promoter 140 may have an effect other than film formation in the heat exchanger 20.

[0024] The injection amount of the dropwise condensation promoter 140 required for film formation and maintenance of the formed film varies depending on factors such as the load on the boiler system 1. Therefore, after the injection of the dropwise condensation promoter 140, surplus dropwise condensation promoter 140 that was not consumed in film formation may be supplied to the boiler section 10 as boiler feedwater 130 by recovering the steam drain.

[0025] When the drop-like condensation promoter 140 is supplied to the boiler section 10, the drop-like condensation promoter 140 adheres to the boiler water tubes 71 and forms a water-repellent film. If a water-repellent film is formed on the boiler water tubes 71, there is a risk that the boiler water tubes 71 will overheat.

[0026] The boiler system 1 of this embodiment can prevent excess dropwise condensation promoter 140 from adhering to the boiler water pipes 71 and forming a water-repellent film, which can cause overheating of the boiler water pipes 71. The boiler system 1 is equipped with a dropwise condensation promoter treatment device 50. The dropwise condensation promoter treatment device 50 is provided in at least one of the drain recovery line 122 and the boiler feedwater line 132, and is a device that removes at least a portion of the dropwise condensation promoter 140 contained in at least one of the drain water 120 flowing through the drain recovery line 122 and the boiler feedwater 130 flowing through the boiler feedwater line 132. The dropwise condensation promoter treatment device 50 can remove excess dropwise condensation promoter.

[0027] The configuration of the dropwise condensation promoter treatment device 50 is not particularly limited. The dropwise condensation promoter treatment device 50 can be, for example, at least one of a filtration device equipped with an adsorbent that adsorbs the dropwise condensation promoter 140, an ion exchange device equipped with an ion exchange material that can exchange ions with the dropwise condensation promoter 140, and a membrane filtration device equipped with a water treatment membrane that is difficult for the dropwise condensation promoter 140 to permeate. By configuring the dropwise condensation promoter treatment device 50 in this way, excess dropwise condensation promoter 140 can be removed with a simple configuration.

[0028] A case will be described in which the dropwise condensation promoter treatment device 50 is provided in the boiler feedwater line 132. When the dropwise condensation promoter treatment device 50 is provided in the boiler feedwater line 132 in addition to the drain recovery line 122, or when it is provided only in the boiler feedwater line 132, the dropwise condensation promoter treatment device 50 is provided in the boiler feedwater line 132 between the recovery tank 30 and the boiler chemical injection unit 60. This prevents the boiler chemicals injected from the boiler chemical injection unit 60 into the boiler feedwater line 132 from being removed by the dropwise condensation promoter treatment device 50.

[0029] As described above, the temperature monitoring unit 72 monitors the temperature of the boiler water pipes 71. When the temperature monitoring unit 72 detects an abnormal rise in the temperature of the boiler water pipes 71, the temperature monitoring unit 72 transmits the detection information to the supply amount adjusting unit 80. The supply amount adjusting unit 80 reduces the amount of the dropwise condensation promoter 140 supplied to the steam line 112 by adjusting the injection speed of the dropwise condensation promoter injector 144, for example. This makes it possible to reliably suppress the supply of excessive dropwise condensation promoter 140.

[0030] Furthermore, in the initial stage of treatment with the dropwise condensation promoter, the surfactant action of the dropwise condensation promoter on previously accumulated corrosion deposits makes the corrosion deposits more likely to peel off. However, by suppressing the supply of excessive dropwise condensation promoter in the present invention, the corrosion deposits are quickly peeled off in the initial stage of chemical injection, which is expected to have the secondary effect of preventing problems caused by clogging of primary filters such as strainers installed in boiler feed systems.

[0031] The method for suppressing the supply of excessive droplet-like condensation promoter 140 as described above can be expressed as follows: That is, the method for controlling the injection of droplet-like condensation promoter 140 in boiler system 1 including boiler section 10 and heat exchanger 20 monitors the temperature of boiler water pipes 71 in boiler section 10, and when an abnormal rise in the temperature of boiler water pipes 71 is detected, at least one of reducing the supply amount of drop-like condensation promoter 140 and removing at least a portion of the supplied drop-like condensation promoter 140 is performed.

[0032] The temperature rise of the boiler water tubes 71 occurs when the dropwise condensation promoter 140 adheres to the inner surface of the boiler water tubes 71, forming a film that makes the surface of the boiler water tubes 71 hydrophobic, resulting in poor water wettability and inhibiting heat transfer from the outer wall of the boiler water tubes 71 to the inner wall of the boiler water tubes 71, resulting in heat being trapped within the boiler water tubes 71 themselves. Therefore, if the amount of dropwise condensation promoter 140 supplied to the boiler section 10 is reduced by the following measures A or B, the amount of dropwise condensation promoter 140 adhering to the inner surface of the boiler water tubes 71 decreases in accordance with its adsorption / desorption equilibrium relationship, thereby restoring heat transfer and eliminating the abnormal rise in temperature of the boiler water tubes 71. Therefore, in the method for controlling the injection of the dropwise condensation promoter, the above-mentioned rise in the temperature of the boiler water tubes 71 is used as a trigger to carry out (A: reduce the supply amount of the dropwise condensation promoter 140) and / or (B: partially remove the dropwise condensation promoter 140).

[0033] The above describes an embodiment of the present invention. The present invention is not limited to the above embodiment, and various modifications, variations, and combinations are possible. For example, the steam line 112 may be provided with a steam header. This allows steam to be supplied to multiple heat exchangers 20, etc.

[0034] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] This disclosure includes matters that contribute to achieving Goal 7 of the SDGs (Sustainable Development Goals), "Affordable and clean energy." [Explanation of symbols]

[0035] 1. Boiler system 10 Boiler section 20 Heat exchanger 30 Recovery Tank 40 Droplet condensation promoter supply section 50 Droplet condensation promoter treatment device 60 Boiler chemical injection section 70 Boiler 71 Boiler water tubes 72 Temperature monitoring section 80 Supply amount adjustment section 110 Steam 112 Steam Line 114 Steam Line Valve 120 Drain water 122 Drain recovery line 130 Boiler feedwater 132 Boiler feedwater line 140 Droplet condensation promoter 142 Droplet condensation promoter injection line 144 Dropwise condensation promoter injection device 190 Raw water 192 Raw Water Supply Line 194 Water softener 196 Degassing device

Claims

1. A boiler system including a boiler and a heat exchanger, a steam line having the other end connected to the heat exchanger for flowing steam from the boiler to the heat exchanger; a drain recovery line having one end connected to the heat exchanger and through which drain water generated by condensation of steam in the heat exchanger flows; a collection tank disposed at the other end of the drain collection line and configured to store the drain water; a boiler feedwater line for supplying the water stored in the recovery tank to the boiler as boiler feedwater; a dropwise condensation promoter supply unit that supplies a dropwise condensation promoter to the vapor line; a dropwise condensation promoter injection line having one end connected to the dropwise condensation promoter supply unit and the other end connected to the steam line, for injecting a dropwise condensation promoter from the dropwise condensation promoter supply unit into the steam line; a dropwise condensation promoter treatment device provided in at least one of the drain recovery line and the boiler feedwater line, for removing at least a portion of the dropwise condensation promoter contained in at least one of the drain water flowing through the drain recovery line and the boiler feedwater flowing through the boiler feedwater line.

2. 2. The boiler system according to claim 1, wherein the dropwise condensation promoter treatment device is selected from at least one of a filtration device having an adsorbent that adsorbs the dropwise condensation promoter, an ion exchange device having an ion exchange material capable of ion exchange with the dropwise condensation promoter, and a membrane filtration device having a water treatment membrane that is difficult for the dropwise condensation promoter to permeate.

3. The boiler feedwater supply system further includes a boiler chemical injection unit that is provided in the boiler feedwater line and that injects a boiler chemical into the boiler feedwater flowing through the boiler feedwater line.

3. The boiler system according to claim 1, wherein the dropwise condensation promoter treatment device is provided between the recovery tank and the boiler chemical injection section.

4. the boiler includes a boiler water pipe that heats water supplied as the boiler feedwater to generate steam, The boiler system includes: a temperature monitoring unit provided in the boiler water tube and configured to monitor a temperature of the boiler water tube; 3. The boiler system according to claim 1, further comprising: a supply amount adjusting unit provided in the dropwise condensation promoter supply unit, which reduces the amount of dropwise condensation promoter supplied when the temperature monitoring unit detects an abnormal rise in temperature of the boiler water tube.

5. A method for controlling injection of a dropwise condensation promoter in a boiler system including a boiler and a heat exchanger, comprising: monitoring the temperature of boiler water tubes in the boiler; reducing the supply amount of the dropwise condensation promoter and removing at least a part of the dropwise condensation promoter that has been supplied when an abnormal rise in temperature of the boiler water tube is detected; A method for controlling the injection of a dropwise condensation promoter, comprising:

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