JP3116042B1 - Liquid circulation system equipment - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To increase a mixing time of circulating water and an oxygen scavenger to increase a deoxygenation reaction time, to improve a reaction efficiency with dissolved oxygen in circulating water to enhance a deoxidizing effect, and to form a circulation path. Provided is a liquid circulation system that can prevent corrosion of piping. A water supply pump (P) for supplying water from a water supply tank (F) to a heat exchanger (X) is provided, and a heat consuming device (Y) for consuming heat energy extracted from the heat exchanger (X) is provided.
And a circulation path V for circulating water again to the water supply tank F through the heat exchanger X and the heat consuming device Y, and replenishes the water supply tank F with water shortage in the circulation path V due to the circulation of the water. In the liquid circulating system equipment provided with the makeup water path V, an oxygen absorber supply device A for supplying the oxygen absorber from an intermediate point of the makeup water path V is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply pump for supplying water from a water supply tank to a heat exchanger, a heat consuming device for consuming heat energy extracted from the heat exchanger, and a heat exchanger from the water supply tank. and a liquid circulation system facilities example Bei a circulation path for circulating the water in the water tank again through the heat consuming device.

[0002]

2. Description of the Related Art For example, in order to prevent corrosion of piping forming a circulation path due to oxygen contained in boiler water, it is necessary to supply an oxygen scavenger which reacts with oxygen to remove the oxygen to the boiler water. The required amount of oxygen scavenger solution is supplied to the boiler water from the oxygen scavenger supply device with the operation of the boiler. In the liquid circulation system, the water in the water supply tank is easily brought into contact with air, and the makeup water is replenished while containing a large amount of dissolved oxygen. Because the amount of dissolved oxygen in the water tends to increase, it is easy to cause corrosion in the piping from the water supply tank to the heat exchanger, and in order to prevent the corrosion of the piping, close to the water supply tank closer to the water supply pump than the water supply pump It is good to supply the oxygen scavenger from the pipe, but since the oxygen scavenger is alkaline, when supplied to the pipe on the upstream side of the water supply pump, the impeller in the water supply pump is actuated by the alkali of the oxygen scavenger. Alkaline corrosion may occur and cause early deterioration and breakage. In addition, the oxygen scavenger may be sucked by the negative pressure of the pump and the supply amount thereof may increase, thus causing deterioration and breakage of the water supply pump. Conventionally, in order to prevent such a situation, a liquid circulating system of this type is configured to supply an oxygen scavenger into a boiler water supply passage K on the lower side of the water supply pump P as shown in FIG. To prevent corrosion of the boiler water supply passage K while protecting the impeller of the water supply pump P and preventing an increase in the supply amount of the oxygen scavenger due to the negative pressure of the water supply pump P.

[0003]

According to the above-mentioned conventional liquid circulating system equipment, it is possible to prevent the impeller in the water supply pump from being corroded by an alkali or the supply amount of the oxygen scavenger from being increased by the negative pressure of the pump. However, due to the configuration that supplies the oxygen scavenger into the pipe on the lower side of the water supply pump, the piping distance to the heat exchanger is shortened accordingly, and the mixing time with the oxygen scavenger is shortened. As a result, it was not possible to take a long time for the deoxidizing treatment, and the deoxidizing efficiency was low.

Accordingly, an object of the present invention is to solve the above-mentioned problems, increase the mixing time of the circulating water and the oxygen scavenger, increase the deoxidation reaction time, and improve the reaction efficiency with the dissolved oxygen in the circulating water. The purpose of the present invention is to provide a liquid circulating system capable of enhancing the deoxidizing effect and preventing corrosion of piping forming a circulation path.

[0005]

[Means for Solving the Problems]

[Configuration] As shown in FIG. 1, a characteristic configuration of the invention according to claim 1 is to provide a water supply pump P for supplying water from a water supply tank F to a heat exchanger, and to consume heat energy extracted from the heat exchanger X. A consuming apparatus Y is provided, and a circulation path Z for circulating water from the water supply tank F to the water supply tank F again through the heat exchanger X and the heat consuming apparatus Y is provided, and the circulation of the water causes shortage in the circulation path Z. A water supply path V for supplying water to the water supply tank F is provided , and a hydrolyzable tannin or a neutral salt thereof is
First liquid storage tank Q for storage and alkali metal hydroxide
A second liquid storage tank R for storing an object.
1, a mixer M for mixing a chemical solution from a second liquid storage tank
The generates a deoxidizer through, in the place where the middle portion of the water supply tank F or the makeup water path V wherein is provided an oxygen scavenger feeder A for supplying an oxygen scavenger.

[0006] As described above, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Action and Effect] According to the invention of claim 1, the hydrolyzable tannin or its tannin
A first liquid storage tank for storing neutral salts, and an alkali metal
A second liquid storage tank for storing hydroxide,
Mixer for mixing chemicals from first and second liquid storage tanks
The generated oxygen scavengers through the from is provided deoxidation agent supply device for supplying the oxygen scavenger in the middle portion of said water supply tank or the makeup water path, improving the deoxidation efficiency As well as a chemical solution that produces oxygen scavengers.
It can be stored and kept in a fixed state . In other words, since the oxygen absorber is supplied into the water supply tank or the water supply path storing the supply water with a large amount of dissolved oxygen, the oxygen removal reaction is effectively performed, and the oxygen absorber stays in the water supply tank. The time required for the deoxidation treatment in the water supply tank can be increased, and the efficiency of the deoxidation treatment can be improved.
In addition, since the alkali of the oxygen scavenger is diluted in the water supply tank, the impeller in the water supply pump provided downstream of the water supply tank may cause alkali corrosion, or the supply amount of the oxygen scavenger due to the negative pressure of the water supply pump. Can be prevented from increasing. With hydrolyzable tannin or its neutral salt
When mixed reaction with alkali metal hydroxide, very acid
Gallic acid and alcohol compounds that react easily with sulfur
That deoxidation Motozai is generated. This oxygen absorber dissolves in water
Because it reacts by absorbing not only oxygen but also oxygen in the air
When storing, keep away from air
Required, making the structure of the storage tank complicated and
Was difficult to handle. However, hydrolysis
Type tannin or its neutral salt and alkali metal hydroxide
Will not cause a deoxygenation reaction if both are used alone
Therefore, in the present invention, the hydrolyzable tannin or its neutral
Salt and alkali metal hydroxide stored in separate storage tanks
When necessary, the hydrolyzable tannin is passed through a mixer.
Or a mixture of the neutral salt and alkali metal hydroxide
Produces oxygen scavenger consisting of citrate and alcohol compounds
To supply water to the makeup water path.
Storage and storage of chemicals that produce
Can be. As a result, the corrosion prevention performance of the piping can be improved , and the storage tank structure can be simplified.
Not only makes it easier to handle, but also
Can be effectively caused without deteriorating .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, portions denoted by the same reference numerals as those of the conventional example indicate the same or corresponding portions. FIG. 1 shows a schematic flow of a boiler facility provided with a deoxidizer supply device A as an example of a liquid circulating system facility according to the present invention, in order to prevent corrosion of piping due to oxygen contained in boiler water. A water supply pump P for supplying water from a water supply tank F to a boiler B (an example of a heat exchanger X) through a boiler water supply path K, and steam (an example of heat energy) generated by the boiler B is passed through a steam path L Therefore, the steam is introduced from C into a steam turbine D (an example of the heat consuming device Y) and converted into kinetic energy. After that, the waste steam converted into the kinetic energy is condensed in the condenser E and returned to water. Is returned to the water supply tank F again through the condensate channel I. The boiler water supply channel K, the steam channel L, and the condensate channel I
A circulation path Z is formed by the boiler water, and the shortage of water in the circulation path Z due to the circulation of the boiler water is supplied to the supply water in the supply water tank G by the supply water pump J from the water softener H to the water supply tank F.
A replenishing water path V for replenishing the replenishing water is provided, and an oxygen-absorbing agent supply device A for supplying an oxygen-absorbing agent is provided at an intermediate position of the replenishing water path V.

The oxygen scavenger supply device A includes a first liquid storage tank Q for storing a hydrolyzable tannin or a neutral salt thereof, and a second liquid storage tank R for storing an alkali metal hydroxide. An oxygen scavenger solution is generated through a mixer M for mixing the chemicals from the first and second liquid storage tanks, and is formed so as to supply the oxygen scavenger from an intermediate point of the makeup water path V. Have been. In the figure, N denotes a hydrolyzable tannin or a neutral salt thereof from the first liquid storage tank Q.
Is a first pump for supplying alkali water hydroxide from the second liquid storage tank R to the makeup water path V via the mixer. Two pumps.

The oxygen scavenger solution is obtained by mixing and reacting a hydrolyzable tannin or a neutral salt thereof with an alkali metal hydroxide to produce a gallic acid salt and an alcohol compound which easily react with oxygen. The gallate is reacted with oxygen contained in boiler water to remove oxygen which causes corrosion of the piping.

As the hydrolyzable tannin, any of quintuple tannin, gallic tannin, tara tannin, chestnut tannin and smack tannin may be used. Any of sodium alkali, potassium alkali, ammonia alkali and the like may be used as the alkali agent for adjusting the temperature. However, it is preferable to use sodium alkali or potassium alkali as an alkali agent and adjust the solution as a strongly alkaline tannin solution.

[Another Embodiment] Another embodiment will be described below. <1> The oxygen scavenger supply device A includes the first liquid storage tank Q for storing the hydrolyzable tannin or its neutral salt described in the previous embodiment, and the second liquid storage tank Q for storing the alkali metal hydroxide.
It is not limited to the one provided with the liquid storage tank R and supplying the oxygen scavenger via the mixer M which mixes the two immediately before the supply. For example, as shown in FIG. A configuration in which a deoxygenating agent composed of an acid salt and an alcohol compound is stored in one storage tank T may be used. However, when this configuration is employed, gallate which is very liable to react with oxygen continuously reacts with air while being stored in the storage tank T and loses the deoxidizing ability. It is necessary to fill T with nitrogen gas to prevent contact with oxygen in the air, or to cover the entire surface of the stored liquid by some method to prevent contact with air. <2> The supply amount of the oxygen absorber from the oxygen absorber supply device A is:
For example, as shown in FIG. 3, a flow meter sensor W for measuring the flow rate of the makeup water is provided on the makeup water path V on the upstream side of the deoxidizer supply point, and the flow rate sensor W is provided based on the detection result of the flow meter sensor W. A configuration including a control device S for controlling the supply amount of the oxygen agent to the makeup water path V may be provided. In addition, a first liquid storage tank for storing the hydrolysis type tannin or its neutral salt by detecting not only the flow rate of the makeup water but also the pH of the makeup water and the water in the water supply tank, and storing the alkali metal hydroxide. It may be configured to control the supply amount from the second liquid storage tank to maintain a constant pH. With this, the deoxygenation process can be performed more effectively without imposing a load on the water supply pump and the piping. <3> The liquid circulation system equipment is not limited to the boiler equipment described in the above embodiment, and may be, for example, a heat pump. In short, the present invention can be applied to equipment having a piping system in which piping is desired to be prevented from being corroded by oxygen in a liquid. <4> The chemical used as the oxygen scavenger is not limited to the composition in which the alkali metal hydroxide is mixed with the hydrolyzable tannin described in the previous embodiment, but may be hydrazine, sodium erythorbate, sodium ascorbate. And sodium sulfite may be used. <5> The supply of the makeup water is not limited to the configuration in which the makeup water is supplied from the makeup water tank by the makeup water pump described in the above embodiment, and may be a configuration in which the makeup water is directly supplied from the water supply. In this case, since the pressure is applied to the tap water in advance, the makeup water can be supplied to the supply tank without providing the makeup water pump. <6> The supply point of the oxygen scavenger is not limited to the one supplied from the middle part of the makeup water path described in the above embodiment, and may be a configuration in which the oxygen scavenger is directly supplied to the water supply tank. .

[0013]

EXAMPLES (Example 1) The removal of dissolved oxygen in service water at room temperature was confirmed while stirring in a 110 ml furan bottle. The dissolved oxygen meter used was manufactured by Central Science Co., Ltd.
D-1 was used. Ion exchange pure water exploded at room temperature was used as the service water. Example 1: Fivefold tannin (hydrolyzed tannin) 2
Immediately after adjusting the solution of 4% and 7% of sodium hydroxide, 500 mg / ml was added to the furan bottle. Example 2: Taratannin (hydrolyzed tannin) 24
Immediately after preparing a solution containing 5% potassium hydroxide and 500% potassium hydroxide, 500 mg / ml was added to a furan bottle. Example 3 A solution of 24% of gallic tannin and 2.4% of sodium hydroxide was prepared (pH of the solution was 9.1).
725 mg / ml was immediately added to the furan bottle. Example 4: Five-fold tannin (hydrolyzed tannin) 2
Immediately after adjusting the solution of 2% and 9% of sodium hydroxide, 100 mg / ml was added to the furan bottle. COMPARATIVE EXAMPLE 1 The measurement was performed by adding 700 mg / ml of a 50% concentration quintuple tannin (hydrolyzed tannin) solution. Comparative Example 2: Kevlarthiotannin (condensed tannin) 2
Immediately after adjusting the solution of 4% and 7% of sodium hydroxide, 500 mg / ml was added to the furan bottle. Comparative Example 3: Fivefold tannin (hydrolyzed tannin) 2
After adjusting 50 ml of a 4% solution of 7% sodium hydroxide, the solution was left standing in a 50 ml beaker for 5 days.
00 mg / ml was added to the furan bottle. Comparative Example 4: Fivefold tannin (hydrolyzed tannin) 2
A solution of 4% and 1% sodium hydroxide was prepared (pH of the solution was 8.5) and 725 mg / ml was immediately added to the furan bottle. Table 1 shows the additive concentration in the flan bottle. Like

[0014]

[Table 1]

Table 2 shows the deoxidizing effect of each additive. It was shown to.

[0016]

[Table 2]

As is evident from Table 2, the effect of gallic acid cannot be obtained with alkali unless it is a hydrolyzable tannin (comparison between Comparative Example 2 and each Example). Is large (from the comparison between Example 1 and Comparative Example 3), and the effect is weak unless the mixing amount of the alkali agent is pH 9 or more (from the comparison between Example 3 and Comparative Example 3).
Is evident. 3 mg of quintuple tannin from Example 4
/ L can also remove 1 mgO ₂ / l of dissolved oxygen.

Example 2 The present invention was implemented in a boiler water supply line used in an actual factory. The conditions of the water supply line were as follows: water supply tank temperature 60 ° C. recovery rate of condensed water 60% dissolved oxygen 7.2 mg O ₂ / l Injection was performed at the rate of injection relative to the amount of soft water when replenishing soft water. Dissolved oxygen meter Toa Denpa Kogyo Co., Ltd. DO-14 type pH meter Toa Denpa Kogyo Co., Ltd. HM-14P type The test was carried out using quintuple tannin and sodium hydroxide.
The test was performed with and without a mixing mechanism. Example 5: The mixing ratio of chemical injection was adjusted so as to obtain a mixed solution of 25 parts of quintuple tannin and 10 parts of sodium hydroxide, and only the combination was carried out without a mixing device, so that quintuple tannin 25 mg / l and sodium hydroxide 10 mg / l
Was added to the soft water replenishment line of the water supply tank at an injection amount relative to the soft water amount of the water. Example 6: The mixing ratio was adjusted by using a mixing device so as to obtain a mixed solution of 25 parts of quintuple tannin and 10 parts of sodium hydroxide, and then mixed using a mixing device.
1 was added to the soft water replenishment line of the water supply tank at an injection amount relative to the soft water amount. Example 7: The mixing ratio was adjusted so that a mixed solution of 25 parts of quintuple tannin and 20 parts of sodium hydroxide was obtained, and after mixing using a mixing device, quintuple tannin 25 mg / l and sodium hydroxide 20 mg / l
1 was added to the soft water replenishment line of the water supply tank at an injection amount relative to the soft water amount. Comparative Example 5: The water supply tank was operated without adding any tannin compound. Table 3 shows the results.

[0019]

[Table 3]

As is clear from Table 3, the dissolved oxygen in the soft water was almost completely removed by the quintuple tannin 25 mg / l (comparison between Comparative Example 5 and each Example). By increasing the mixing efficiency of the tannin and the alkali agent and increasing the degree of gallic acid production (comparing Example 5 with Examples 6 and 7), good dissolved oxygen removal became possible. Furthermore, when the tannin of the present invention was not added, the iron ion in the steam condensate collected in the condensate tank was present at 0.8 mg / l, but the dissolved oxygen was removed up to Example 7. By feeding the boiler, the condensate in the condensate tank was reduced to 0.2 mg / l of iron ions. This not only prevents corrosion in the water supply pipes and boiler cans, but also reduces the corrosion caused by condensed water in the steam line.

[Brief description of the drawings]

FIG. 1 is a schematic flowchart of a boiler facility showing an embodiment of the present invention.

FIG. 2 is a schematic flow chart of a boiler facility showing another embodiment of the present invention.

FIG. 3 is a schematic flow chart of a boiler facility showing another embodiment of the present invention.

FIG. 4 is a schematic flowchart of a conventional boiler facility.

[Explanation of symbols]

 P water pump F water tank X heat exchanger Y heat consuming device Z circulation path V makeup water path A deoxidizer supply device T storage tank Q first storage tank R second storage tank W flow meter sensor S controller

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-89981 (JP, A) JP-A-61-8707 (JP, U) Japan Boiler Association, “Boiler Technology Course, Boiler Water Management” , First Edition, Kyoritsu Shuppan Co., Ltd., October 5, 1969, p. 143-158 Mitsuaki Kiwaki, "Boiler Water Supply and Treatment", 4th edition, Chira Shobo Co., Ltd., May 25, 1965, p. 206-208 (58) Field surveyed (Int.Cl. ⁷ , DB name) F22D 11/00 F22B 37/00 F22B 37/52

Claims (1)

(57) [Claims] 1. A water supply pump for supplying water from a water supply tank to a heat exchanger, a heat consuming device for consuming heat energy extracted from the heat exchanger, and a heat consuming device passing from the water supply tank through the heat exchanger and the heat consuming device. comprising a circulation path for circulating the water in the water tank again Te, a water shortage in the circulation path by circulating the water with a makeup water path for supplying to the water tank, the hydrolyzable tannins or a neutral salt Store
First liquid storage tank and stores alkali metal hydroxide
A second liquid storage tank, wherein the first and second liquid storage tanks are provided.
Oxygen absorber through a mixer that mixes the chemical from the storage tank
To generate, the water supply tank or the oxygen absorber feeder liquid circulation system equipment is provided for supplying an oxygen scavenger in the middle portion of the makeup water path.