JP2000039104A - Method and device for injecting chemical into boiler feedwater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively, safely, and surely manage the quality of the feedwater to a boiler, by injecting a chemical into a condensate tank by using a medical instiller. SOLUTION: Since the condensate from a condenser 9 is returned to a condensate tank 1 when pure water is supplied to the tank 1, the supply of the pure water from a pure water device fills up the tank 1 containing an insufficient amount of water. A chemical containing a boiler compound and an oxygen scavenger is injected into the pure water and condensate in the tank 1 from a medical instiller 10, and the compound and scavenger are mixed with the pure water and condensate by means of a line mixer 31 installed to the outlet of the tank 1. The water mixed with the chemical is sent to a deaerator 3 by means of a feed water pump 2 for deaerator, and deaerated water is physically produced by the superheated steam from a high-pressure steam pocket 7. In addition, dissolved oxygen is also removed chemically by the mixed oxygen scavenger. Therefore, the quality of the feedwater to a boiler can be managed inexpensively, safely, and surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for injecting a chemical for boiler feedwater into which a chemical for water quality control is injected.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open Nos. Sho 52-67063, 63-131910, and Hei 1-16351 describe inventions related to this type of conventional liquid injector.
No. 0 and JP-A-4-324003 are disclosed. Of the inventions disclosed in each of these publications, JP-A-63-131910 and JP-A-1-16351
FIG. 6 and FIG. 7 show the configuration of the apparatus described in Japanese Patent Publication No. 0.
In FIG. 6, 101 is a boiler, 102 is a water level gauge, 10
3 is a water supply control unit, 104 is a water supply pump, 105 is a chemical solution pump, 106 is a chemical solution tank, and 107 is a combustion control unit. Reference numeral 108 denotes a chemical solution supply stopping unit, 109 denotes a chemical solution concentration detector, and 110 denotes a comparator. S1 is a water supply command signal, S2 is a detection signal of ph or electric conductivity, S3
Is a chemical liquid supply stop command signal.

In the apparatus shown in FIG. 6, the water supply control unit 103 controls the boiler water supply of the water supply pump 104 and the chemical solution of the chemical solution pump 105 at a fixed ratio, and the boiler 101
Supplied to When the operation of the boiler 101 is continued while being controlled by the combustion control unit 107, the chemical solution of the can water is condensed, and the ph value and the electric conductivity increase, and the values are detected by the detector 1.
09 is detected. The detection signal S2 of the detector 109 is sent to the comparator 110 and compared with the set value. Based on the comparison result, the chemical supply stop command signal S3 is sent to the chemical supply stop means 8 and the chemical pump 5 is stopped.

In FIG. 7, reference numeral 204 denotes a water supply pipe, 205 denotes a water supply pump, and 206 denotes a boiler. 216 is an oxygen absorber tank, 217 is an oxygen absorber pump, 218 is a cleaning agent tank, 219 is a cleaning agent pump, 220 and 223 are control devices, 221 is a temperature detector, and 222 is a ph detector. . The apparatus for injecting a chemical solution into the boiler feedwater having a configuration as shown in FIG. 7 detects the temperature of the boiler feedwater and the ph value which change according to the amount of dissolved oxygen in the boiler 201 and the ph value.
21 and ph detector 222. Then, the oxygen scavenger pump 217 and the scrubber pump 219 are adjusted by the two control devices 220 and 223 such that the oxygen scavenger and the scrubber have a required flow rate corresponding to the detected temperature signal.

[0005] In addition, although the drawing showing the structure of the chemical liquid injection device is omitted, in the case of the above-mentioned chemical liquid injection device with a stirrer disclosed in Japanese Patent Application Laid-Open No. 52-67063, the rotor is driven by a motor into a dilution tank to perform injection. A stirrer that constantly stirs the inside of the dilution tank during the operation of the pump is provided. In addition, Japanese Unexamined Patent Publication No.
In the hydrazine stock solution feeding device of No. 324003, two level switches, high and low, are provided in the stock solution tank, and both switches open and close the automatic valve of the stock solution supply pump to control the amount of hydrazine stock solution in the stock solution tank to a certain range. It has become so.

[0006]

The liquid injector disclosed in Japanese Patent Application Laid-Open No. 63-131910 shown in FIG. 6 in the inventions described in each of the above publications has a ph value and electric conductivity of canned water as described above. When the value reaches a predetermined set value, the injection of the chemical solution is stopped by the chemical solution supply stopping means 108 so that wasteful consumption can be prevented. However, in the apparatus shown in FIG. 6, the chemical liquid supply stopping means 108 between the water supply control unit 103 and the chemical liquid pump 105, the electric conductivity detector 109 in the can, and the set value and the detection value of the detector 109 are used. A comparator 110 and the like for comparison are provided, and these are electrically connected to each other by wiring. Further, a pipe for injecting the chemical solution in the chemical solution tank 106 into the boiler feedwater by the chemical solution pump 105 is also connected, and the overall configuration of the chemical solution injection device is extremely complicated and expensive.

On the other hand, JP-A-01-163 shown in FIG.
No. 510 “Injection device for chemical liquid into boiler feed water” for injecting oxygen scavenger and cleansing agent into tanks 216 and 218 for dilution and pumps 217 and 219, respectively, in addition to the undiluted liquid tank, and dedicated for chemical liquid injection Are provided. In addition, as described in the upper right column on page 43 of the same publication, a stirrer, a control panel for automatic dilution and injection amount adjustment are also provided, and it is necessary to adjust the rotation speed and stroke of the pump for water quality management. Further, in the case of JP-A-52-67063 and JP-A-04-32003, which are not shown, a stirrer for stirring by a motor is provided, and two level switches for controlling the liquid level of the stock solution tank are provided. An automatic valve is provided, and both of the devices described in these publications have problems such as a complicated structure.

The inventor of the present application has conducted various experiments and studies to solve the above-mentioned problems of the conventional apparatus, and has conducted an experiment on a chemical liquid injection apparatus for boiler feed water with respect to the structure of a stirrer, a chemical liquid injection pump, a pipe for injection, and the like. Various experiments and studies were conducted. Then, the invention of the present application provided with a method and an apparatus for charging a boiler feedwater with a chemical solution as described in the section [Means for Solving the Problems] below. As a result, according to the present invention, the chemical tank, the dilution tank, the stirrer, and the chemical injection pump are no longer required for the conventionally used cans and deoxidizers. For chemicals, a dedicated pipe from the pump to the boiler feed water (boiler drum) and a control panel for automatic dilution / injection volume control for cleanser, and a dedicated pipe from the pump to the deaerator for deoxidizer And the control panel for automatic dilution and injection volume adjustment could be omitted.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a chemical liquid injection method for injecting a liquid chemical for water quality management in a thermal circulation system for boiler feed water and steam condensate including a boiler and a condensate tank. It adopts a chemical liquid injection method for boiler feed water in which a chemical liquid is injected using a medical dropper.
Further, in the chemical liquid injection method according to the above item 1, a chemical liquid injection method for boiler feed water, in which a deoxidizing agent, a cleaning agent and a condensing agent are injected as the chemical liquid, is adopted. Further, in the chemical liquid injection method described in the above 1 or 2, a chemical liquid injection method of boiler water supply in which a mixer for boiler water supply and a chemical liquid is provided on the outlet side of the condensate tank and mixed is adopted. Further, in the chemical liquid injection method described in the above item 3, a chemical liquid injection method for boiler feed water in which a mixer is mixed with a line mixer is adopted.

Further, in a chemical liquid injector for injecting a chemical for water quality management in a thermal circulating system for boiler feed water and steam condensate including a boiler and a condensate tank, a medicament for injecting a chemical into the condensate tank is provided. Of the boiler feed water provided with a line mixer for mixing the boiler feed water and the chemical solution on the outlet side of the condensate tank.

From the pure water apparatus, pure water is supplied to a condensate tank. During operation, the condensate is returned from the condenser to the condensate tank, so the pure water is used for replenishing the water shortage. The pure water and the condensate thus placed in the condensate tank are filled with a chemical from a dropper for medicine and mixed by a line mixer provided at the outlet of the condensate tank. The mixed water of the chemical is sent to the deaerator by the deaerator water supply pump, and the deheated water is physically created by the superheated steam. Also, the dissolved oxygen is removed chemically and degassed by the mixed deoxidizing agent. The ph value of the boiler feedwater is adjusted by the chemical action of the injected and mixed cleaning agent.

The degassed water degassed by the degasser is supplied to the boiler drum via the economizer by the boiler water supply pump. The steam generated in the boiler drum is sent to a high-pressure steam reservoir via a superheater. Further, the steam stored in the high-pressure steam reservoir is supplied to a steam turbine to generate power and convert steam energy into electric energy. The steam that has worked in the steam turbine is sent to a low-pressure steam condenser where it is cooled and returned to condensate. Then, the returned condensate is returned to the condensate tank, and the chemical is again injected into the condensate tank, and then sent to the boiler to repeat the cyclic operation.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of the first embodiment of the present invention, FIG. 2 is a side view showing a configuration of a usage example of the present invention, and FIG. 3 is an enlarged side view of the V clamp of FIG. FIG.
, 1 is a condenser tank of the condenser. 2 is a deaerator water pump, 3 is a deaerator, 4 is a boiler water pump, 5 is an economizer, and 6 is a boiler (boiler drum) having a superheater 60. The economizer 5 is mounted inside the boiler 6 or in the flue so as to heat the boiler feed water and recover heat. Reference numeral 7 denotes a high-pressure steam reservoir, 8 denotes a turbine generator constituting a load, and 9 denotes a low-pressure steam condenser. The thermal energy of the boiler feed water and steam condensate is conveyed by a closed loop in which the feed water sent from the condensate tank 1 is vaporized by the boiler 6 and the condensed steam vaporized through the condenser is returned to the condensate tank again. Is constituted.

M is a chemical injection device for water quality management according to the present invention. FIGS. 2 and 3 show the configuration of a specific usage example of the chemical liquid injector M. FIG. In the chemical liquid injection device M,
A dropper 10 for medicine as shown is used.
Numerals 11, 12, and 13 denote containers each containing a chemical solution.
A cleaning agent A and a deoxidizing agent B are enclosed in 1 and 12, respectively. Also,
The container 13 contains another chemical C, for example, a condensate. For example, when the drum pressure of the boiler 6 is high as the cleaning agent A, a mixture of the second sodium phosphate and the third sodium phosphate is used and the phosphoric acid treatment is performed. Also,
As the condensing agent C, morpholine (C ₄ H ₈ ON
H), an amine [C ₆ H ₁₁ NH ₂ or RNH ₂ (R = C ₁₀
~ C ₁₂ )], the ph value during condensing is adjusted.

By controlling the ratio between the phosphate ions (PO ₄ ³⁻ ) and the sodium ions (Na ⁺ ), the corrosion of the boiler 6 is prevented. When the drum pressure of the boiler 6 is low, the mixture is treated with alkali using a mixture of polymerized sodium phosphate and an alkali agent. By the alkaline treatment of the boiler feed water, the ph value is adjusted, and the corrosion of the boiler 6 can be prevented as in the case of the phosphoric acid treatment. On the other hand, hydrazine (H ₂ N ₄ ) is used as the deoxidizing agent B, and the dissolved oxygen in the boiler feedwater is changed to water and nitrogen by a chemical change. Then, the ph value of the boiler feedwater is adjusted, and JIS
In accordance with the specified amount.

Reference numeral 14 denotes an infusion stand for holding the containers 11 to 13, and reference numeral 15 denotes an infusion set. 16 is an infusion set 15
, 17 is a connecting pipe, 18 is a V clamp, 1
9 is an adjusting wheel of the V clamp 18. By rotating the adjustment wheel 19 of the V clamp 18 and monitoring the infusion state of the chemical such as the cleaning agent A, the injection amount of the chemical is adjusted. The amount of infusion of the infusion device 10 for medicines can be varied in the range of 2000 cc / h to 20 cc / h (using a syringe needle). 21 is an infusion tube,
22 is a filtration network joint, 23 is an octopus tube. Also,
Reference numeral 25 denotes a two-way stopcock, and reference numeral 26 denotes an injection tube.
The tip of the drip tube 16 of the infusion set 15 is
1 to 13 connected to the liquid medicines A to C in the containers 11 to 13
Is intermittently injected from the injection tube 26 into the condensate tank 1.

Reference numeral 30 denotes a mixer provided on the outlet side of the condensate tank 1. Although illustration is omitted in the mixer 30, in the first embodiment, a line mixer 31 in which a spiral groove is formed on the inner peripheral surface of the pipe is applied. Then, when the boiler feedwater flows out of the outlet of the condensate tank 1, a spiral swirl flow is given to the flow of the boiler feedwater by the spiral groove formed on the inner peripheral surface. As a result, the flow of the boiler feedwater flowing out by the line mixer 31 is swirled, and the chemicals such as the cleaning agent A and the deoxidizing agent B injected in the condensate tank 1 are stirred and uniformly mixed. .

The operation of the first embodiment having the above configuration will be described below. First, pure water is put into the condensate tank 1 from a pure water device. First, a pure water condensate tank 1
After that, the condensate is returned from the condenser 9 so that the supply of the deionized water from the deionized water device is a supplement of the shortage amount.
The pure water and the condensate in the condensate tank 1 are used for a dropper 10 for medicine.
A chemical solution containing a cleaning agent A and a deoxidizing agent B is injected from the tank and mixed by the above-described operation by the line mixer 31 provided at the outlet of the condensate tank 1. The mixed water of the chemicals A to C is sent to the deaerator 3 by the deaerator water supply pump 2, and the deaerated water is physically produced by superheated steam from the high-pressure steam reservoir 7 described later. Also, the dissolved oxygen is chemically removed by the mixed deoxidizer B. Similarly, the ph value of the boiler feedwater is adjusted by the chemistry of the injected cleaning agent.

The actual injection operation of the chemical liquid injection device M is performed in such a manner that the amount of the cleansing agent corresponding to the ph value and the electric conductivity in the can water and the amount of the deoxidizing agent corresponding to the amount of hydrazine remaining in the can water by manual analysis are all the same. It is adjusted by the V clamp of the dropper 10 for use.
An example of the adjustment is as follows. As described above, the dropper 10 for pharmaceuticals has an infusion amount of 2000 cc / h.
The range of up to 20 cc / h can be adjusted. In the medicine dropper 10 of this embodiment, 15 drops correspond to 1 (ml). Therefore, the required amount of chemical is x (ml / h)
Then, the number X of infusions per minute is as follows: X = (15 ×) / 60 (drops) By rotating the adjustment wheel 19 of the V clamp 18, X
A predetermined injection amount of (drops) is set by visual observation of the drip tube 16. Since the frequency of changing the ph value and the like in the canned water is extremely low, sufficient adjustment can be performed by manual operation.

The degassed water deaerated by the deaerator 3 is supplied to the boiler drum 6 via the economizer 5 by the boiler feed pump 4. The steam generated in the boiler drum 6 is
It is sent to the high-pressure steam reservoir 7 via the superheater 60. The steam stored in the high-pressure steam reservoir 7 is supplied to a steam turbine 8 and rotates the turbine to generate power. The steam that has worked in the steam turbine 8 is sent to a low-pressure steam condenser 9 where it is cooled and then condensed. Then, the condensate of the steam is returned to the condensate tank 1, and the above operation is cyclically repeated again.
The high-pressure steam in the high-pressure steam reservoir 7 is sent to the deaerator 3 through a bypass flow path shown by a broken line, and contributes to the removal of the dissolved oxygen by the superheated steam.

The problem expected in the chemical treatment accompanying the implementation of the first embodiment of the present invention can be solved as follows. a. For boiler cleaning chemicals, boiler compound A (PO ₄ ^3-) and deoxidizer B (H ₂ N ₄₎ do not react with each other, it is possible to simultaneously injected into the same place. b. Since the cleaning agent A does not thermally decompose, it does not react with O ₂ when dewatering the feedwater in the deaerator 3, and is not discharged from the vent together with O ₂ discharged during degassing. c. If the pure water is contaminated with pure water, scale (apatite; calcium phosphate) may be formed at the nozzle of the deaerator 3 and clog the nozzle. However, a pure water device is used (purity 0 to 30 micron). Siemens) is no problem. d. Since the condensate tank 1 has an open-to-atmosphere structure, there is no problem in the amount of used chemicals and safety and hygiene because there is a small possibility that the chemicals escape. In particular, all chemicals are in container 1
Since it is used while being sealed and housed in 1, 12,..., There is no need to consider the hygiene hazard of toxic hydrazine.

FIG. 4 is a side view showing a configuration of another use example of the present invention. In the usage example shown in FIG. 4, a medicine dropper 10 using two containers 11 and 12 is used for a chemical liquid injector M for boiler feed water. And containers 11 and 1
2 contains a cleaning agent A and a deoxidizing agent B as described above. In addition, a simple three-way cock 25 is connected in place of the double / three-way cock of Use Example 1. Although there are some differences in the shapes and the like of the containers 11 and 12 containing the liquid medicine and the infusion stand 14, the operation of injecting the liquid medicine is the same, and the description is omitted.

As described above, according to the present invention, not only a wide space for arranging the devices as in the prior art, but also various components and a control panel are unnecessary, and the cost for installing the equipment is low, and it is safe and reliable. Water quality control of boiler feedwater can be performed. In particular, since the medicine dropper 10 is used in the chemical liquid injector M for boiler feed water, there is no need for special wiring and piping, and the device can be made small and inexpensive. In addition, the chemical solution is injected into the condensate tank 1 at the uppermost stream of the circulation system S, and the boiler feed water is stirred by the line mixer 31 having no drive source at the outlet of the condensate tank 1. Therefore, the chemical liquid is automatically and uniformly mixed with the boiler feed water while flowing through the long flow path, and the degassing action with the cleaning can is effectively performed. The device can be provided.

FIG. 5 is a block diagram showing a case where the conventional chemical liquid injection device M constituted by the above-mentioned Japanese Patent Application Laid-Open No. 52-67063 is applied to the circulation system of the first embodiment shown in FIG. become that way. FIG. 5 is a comparison block diagram for explaining the configuration of the present invention. In FIG. 5, a is a cleaning agent in a tank, b is a deoxidizer in a tank, k is a stirrer, m
Is a motor, Pa is a control panel for adjusting the injection amount, pi is a dedicated pipe for the injection device of the boiler feedwater, pu is a pump, t
Is a dilution tank. Comparing the block diagrams of FIG. 1 and FIG. 5, the configuration of the downsizing and simplification of the boiler feed water chemical injection device M using the medicine dropper 10 of the present application is apparent. Table 1 below shows a comparison table of the configurations in both figures.

[0025]

[Table 1]

[0026]

The present invention relates to a method for injecting a chemical for water quality management in a thermal circulation system for boiler feed water and steam condensate including a boiler and a condensate tank. A chemical solution injection method for boiler feed water, in which a chemical solution is injected using a vessel, was adopted. Further, in the chemical liquid injection method described in 1 above, a chemical liquid injection method of a boiler feed water in which a deoxidizing agent, a cleaning agent and a condensing agent are injected as the chemical liquid is adopted.
In the method for injecting a drug solution according to the above 1 or 2,
A chemical liquid injection method was adopted in which a mixer for the boiler water supply and the chemical liquid was provided on the outlet side of the condensate tank to mix the boiler water. Also,
In the chemical liquid injection method described in 3 above, a chemical liquid injection method of boiler feed water mixed with a mixer using a line mixer is employed.

Further, in a chemical liquid injector for injecting a chemical liquid for water quality management in a thermal circulation system for boiler feed water and steam condensate including a boiler and a condensate tank, a medicine for injecting a chemical liquid into the condensate tank is provided. And a chemical mixer for boiler feed water provided with a line mixer for mixing the boiler feed water and the chemical on the outlet side of the condensate tank.

According to the method and apparatus for injecting a chemical solution into a boiler of the present invention, the water quality of the boiler feedwater can be managed by a wide arrangement space of the components, a complicated and expensive group of components, a control panel for adjusting the injection amount, or an injection position. Since there is no need for dedicated piping, there is an advantage that inexpensive, safe and reliable boiler water quality management can be performed. Therefore, according to the present invention, it is possible to provide a safe, small, and compact chemical solution injection method for boiler feed water and a device therefor, which are simple and easy to handle.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a side view showing a configuration of a usage example of the present invention.

FIG. 3 is an enlarged side view of the V clamp of FIG. 2;

FIG. 4 is a side view showing a configuration of another use example of the present invention.

FIG. 5 is a comparison block diagram for explaining the configuration of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional device.

FIG. 7 is a block diagram showing a configuration of another conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Condenser tank 2 Deaerator feed pump 3 Deaerator 4 Boiler feed pump 5 Economizer 6 Boiler 7 High-pressure steam reservoir 8 Turbine generator 9 Low-pressure steam condenser 10 Dropper for pharmaceutical products 11, 12, 13 Container 14 Infusion Stand 15 Infusion set 16 Infusion tube 17 Connecting tube 18 V clamp 19 Adjusting wheel 21 Infusion tube 22 Filtration network joint 23 Octopus tube 25 Double-type three-way cock 26 Injection tube 30 Mixer 31 Line mixer 60 Superheater a Cleaning agent b Deoxidizer k Stirrer m Motor pu Injection pump pi Dedicated piping Pa Control panel t Dilution tank A Cleaning agent B Deoxidizer C Other chemicals M Chemical injection device S Circulation system

Claims (5)

[Claims] 1. A chemical solution injection method for injecting a chemical solution for water quality management in a thermal circulation system for boiler feedwater and steam condensate including a boiler and a condensate tank, wherein a drug dropper is used for the condensate tank. A chemical solution injection method for boiler feed water, characterized by injecting the chemical solution. 2. The method according to claim 1, wherein a deoxidizing agent, a cleaning agent and a condensing agent are injected as the chemical. 3. The chemical liquid injection method according to claim 1, wherein a mixer for mixing the boiler water and the chemical liquid is provided on the outlet side of the condensate tank and mixed. . 4. The chemical liquid injection method according to claim 3, wherein the mixer is mixed with the mixer using a line mixer. 5. A chemical liquid injector for injecting a chemical for water quality management in a thermal circulation system for boiler feedwater and steam condensate including a boiler and a condensate tank, wherein the chemical liquid is injected into the condensate tank. A chemical liquid injector for boiler feed water, comprising: a dropper for medicines; and a line mixer for mixing the boiler feed water and the chemical liquid at the outlet side of the condensate tank.