KR20220115376A - Heating water composition for boiler for reducing energy - Google Patents

Abstract

The present invention relates to a heating water composition for an energy-saving type boiler, that can improve heat transfer efficiency by inhibiting the corrosive action of the heating water composition for the boiler composed of ethylene glycol and water as main components. The present invention protects the environment by replacing the conventional inorganic acid-based corrosion inhibitor like nitrates or phosphates, which are causes of environmental pollution, with an organic salt-based corrosion inhibitor, improves heat transfer efficiency by suppressing the pH drop of the heating water composition with an imidazole-based corrosion inhibitor, which is an organic salt-based compound, to improve the anticorrosive performance, and in addition, suppresses the corrosion in the pipe to enhance heat transfer efficiency by removing bubbles using an anti-foaming agent since the bubbles, generated by various causes when the heating water composition is used for a long time, may perform a pipe corrosion-promoting action.

Description

Heating water composition for boiler for reducing energy

The present invention relates to a heating water composition for an energy-saving boiler, and more specifically, by adding an organic-based corrosion inhibitor that has a buffering action to a mixture containing glycols and water as the main components, suppressing corrosion and improving heat transfer efficiency. It relates to a heating water composition for an energy-saving boiler characterized in that.

For heating water for boilers, tap water has been commonly used, but tap water used as heating water corrodes the internal combustion engine and piping of the boiler to generate scale, which causes poor circulation of heating water and lowers thermal efficiency. In recent years, most of the purified glycol is being replaced by heating water for boilers mainly composed of purified glycol as it causes problems such as a decrease in heat transfer efficiency or clogging of pipes due to precipitation of scales and the like.

As techniques for solving the above problems, heating water compositions for boilers such as Patent Documents 1 to 4 have been developed, and such heating water compositions for boilers are typically used for heating water circulating inside the pipe after about 2 years have elapsed. As the capacity is reduced, problems as described below occur.

In particular, although the present applicant has also developed Patent Documents 1 and 4 and a heating water composition for boilers and received patent registration, the heating water compositions for boilers of Patent Documents 1 to 4, including the patents registered by the present applicant, are corrosion inhibitors. As an inorganic acid-based compound such as nitrate or phosphate is used as a compound, it may cause environmental pollution such as eutrophication and red tide when discarded.

And when the heating water composition for boiler is used for a long period of 2 years or more, the glycol compound, which is the main component, is oxidized by thermal decomposition as a polyhydric alcohol compound. There are problems in that the ability is lowered and the pipe and its accessories are corroded.

In addition, when the heating water composition for a boiler is used for a long period of time, bubbles are generated in the heating water composition due to various causes, and the heat transfer performance is reduced by these bubbles, and it acts to promote corrosion of the heating pipe and its accessories. .

Patent Document 1: Domestic Registered Patent Publication No. 10-0422066 (2004.03.10. Announcement) Heating water composition for boiler Patent Document 2: Domestic Registered Patent Publication No. 10-0626268 (September 20, 2006 Announcement) Heating water composition for boiler Patent Document 3: Domestic Patent Publication No. 10-2008-0053549 (published on June 16, 2008) Heating water composition for boiler Patent Document 4: Domestic Patent Publication No. 10-1546935 (Notice on August 24, 2015) Heating water composition for boiler

Therefore, the present invention protects the environment by replacing the conventional inorganic acid salt-based corrosion inhibitors such as nitrate-based or phosphate-based corrosion inhibitors, which are causes of environmental pollution, with organic salt-based corrosion inhibitors as a way to solve the problems described above, and An object of the present invention is to provide an energy-saving heating water composition for boilers, characterized in that by improving the anticorrosive performance by suppressing a decrease in the pH of the heating water composition for boilers by an imidazole-based corrosion inhibitor, which is a salt-based compound, heat transfer efficiency is increased.

In addition, the present invention suppresses the occurrence of corrosion in the pipe by removing the bubbles in the composition by using an antifoaming agent because the bubbles generated by various causes promote corrosion of the pipe when the heating water composition for a boiler is used for a long period of time. Another object of the present invention is to provide a heating water composition for an energy-saving boiler, characterized in that it improves heat transfer efficiency.

The heating water composition for an energy-saving boiler according to the present invention is a means for solving the above problems. 0.05-2.0 parts by weight of an imidazole-based corrosion inhibitor, 0.5-2.0 parts by weight of a triazole-based corrosion inhibitor, 0.1-2.0 parts by weight of a benzoate, 0.1-2.0 parts by weight of a pH adjuster, 0.01-1.0 parts by weight of a stabilizer, and 0.01-0.1 parts by weight of an antifoaming agent It is characterized in that it consists of parts.

And the purified glycol aqueous solution consists of 70 to 80% by weight of purified glycol and 20 to 30% by weight of water, and the purified glycol is characterized in that it is purified ethylene glycol or purified propylene glycol.

In addition, the imidazole-based corrosion inhibitor is selected from 1-methylimidazole, 1-ethylimidazole, 1-phenylimidazole or benzimidazole or a mixture thereof, and the triazole-based corrosion inhibitor is 1 , 2,3 benzotriazole or 1 to 3 parts by weight, selected from toritriazole, or a mixture thereof.

The present invention protects the environment by using an organic salt-based corrosion inhibitor instead of a conventional inorganic acid-based corrosion inhibitor such as a nitrate-based or phosphate-based corrosion inhibitor, which is a cause of environmental pollution, and uses an imidazole-based corrosion inhibitor, which is an organic salt-based compound, for heating water for boilers. It has the effect of improving the heat transfer efficiency by suppressing the decrease in the pH of the composition to improve the anticorrosive performance.

In addition, in the present invention, when the heating water composition for a boiler is used for a long period of time, the bubbles generated by various causes act to promote corrosion of the pipe, so that corrosion occurs in the pipe by using an antifoaming agent to remove the bubbles in the composition. It has the effect of suppressing the heat transfer efficiency.

The present invention for achieving the above effect relates to a heating water composition for an energy-saving boiler, only the parts necessary for understanding the technical configuration of the present invention are described, and the description of other parts is common in the technical field to which the present invention belongs The description of the configuration and operation to the extent that a person with the knowledge of

Hereinafter, the heating water composition for an energy-saving boiler according to the present invention will be described as follows.

The heating water composition for energy-saving boilers according to the present invention (hereinafter referred to as 'heating water composition') is an energy-saving heating water composition containing purified glycol and water as main components, based on 100 parts by weight of purified glycol aqueous solution, 0.05-2.0 parts by weight of an imidazole-based corrosion inhibitor, 0.5-2.0 parts by weight of a triazole-based corrosion inhibitor, 0.1-2.0 parts by weight of a benzoate, 0.1-2.0 parts by weight of a pH adjuster, 0.01-1.0 parts by weight of a stabilizer, and 0.01-0.1 parts by weight of an antifoaming agent It is characterized in that it consists of parts.

The purified glycol aqueous solution is preferably composed of 70 to 80% by weight of purified glycol and 20 to 30% by weight of water.

The purified glycol compound used in the present invention acts to prevent the temperature of the heated heating water composition from lowering, and to prevent freezing of the heating water in the winter season, which is sub-zero weather, so that the pipe is not frozen.

As for the purified glycol, specifically, it is preferable to use purified ethylene glycol or purified propylene glycol, and more preferably, purified ethylene glycol is used. Since refined glycols do not have anti-corrosion ability by themselves, various anti-corrosive agents must be added.

When the content of purified glycol in the heating water composition is less than 70% by weight of purified glycol, the freezing point increases, so there is a risk that the boiler internal combustion engine and piping may freeze during severe cold. Since the amount of water is small compared to the content of the refined glycol, the additive is not completely dissolved.

The corrosion inhibitors used in the present invention protect the environment by replacing conventional inorganic acid salt-based corrosion inhibitors such as nitrate-based or phosphate-based corrosion inhibitors, which are causes of environmental pollution, with organic salt-based anticorrosive agents that act as a buffer, and the heating water composition for boilers. It is characterized by improving the heat transfer efficiency by suppressing the decrease in pH and improving the anticorrosive performance.

The imidazole-based corrosion inhibitor is an organic acid-based compound for preventing corrosion of copper and iron, and serves to prevent corrosion of pipes and prevents the pH from lowering when the heating water composition is used for a long period of time. acts to inhibit

Specifically, the imidazole-based corrosion inhibitor is preferably selected from among 1-methylimidazole, 1-ethylimidazole, 1-phenylimidazole and benzimidazole, or a mixture thereof.

The imidazole-based corrosion inhibitor is preferably added in an amount of 0.05 to 2.0 parts by weight based on 100 parts by weight of the purified glycol aqueous solution. When the amount of the imidazole-based corrosion inhibitor added is less than the above-limited range, when the pH of the heating water composition is lowered, the pH buffering action does not work properly, so there is a risk that the corrosion inhibitory performance may decrease, and the addition amount is limited as described above. When it exceeds one range, there is a risk of lowering other physical properties of the heating water composition rather than the pH buffering action in proportion to the added amount of the imidazole-based corrosion inhibitor.

And the triazole-based corrosion inhibitor is an organic acid-based compound for preventing corrosion of copper and aluminum, which is a substitute compound for conventional inorganic acid-based corrosion inhibitors such as nitrate-based or phosphate-based corrosion inhibitors, which are causes of environmental pollution, protecting the environment and preventing corrosion It improves performance and increases heat transfer efficiency.

Specifically, the triazole-based corrosion inhibitor is preferably selected from 1,2,3 benzotriazole or 1 to 3 parts by weight, toritriazole, or a mixture thereof.

The triazole-based corrosion inhibitor is preferably added in an amount of 0.5 to 2.0 parts by weight based on 100 parts by weight of the purified glycol aqueous solution. When the addition amount of the triazole-based corrosion inhibitor is less than the above-limited range, there is a risk of deterioration of corrosion inhibitory performance. Performance is not improved, but there exists a possibility that other physical properties of a heating water composition may be reduced on the contrary.

In the present invention, the pH adjuster maintains the pH of the heating water composition at 7.5 to 9.0 to prevent corrosion in the pipe to prevent the formation of scale, and replaces conventional inorganic salt-based compounds such as sodium hydroxide and potassium hydroxide. It is preferable to use cyclohexylamine which is an organic salt type compound as a compound.

Cyclohexylamine is an organic strong base compound that is well soluble in water or organic solvents, and has a pH of 11.5 (at 100 g/L, 20°C).

The pH adjusting agent is preferably added in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the purified glycol aqueous solution. The amount of the modifier added is not necessarily limited to the ranges listed above, and may be appropriately adjusted according to the state of the pH value of the heating water composition.

The benzoate is a corrosion inhibitor for inhibiting corrosion of cast iron and carbon steel, and specifically, it is preferable to use sodium benzoate.

The amount of benzoate added is preferably 0.1 to 2.0 parts by weight based on 100 parts by weight of purified glycol aqueous solution. When the amount of benzoate added is less than the above-limited range, there is a risk of corrosion due to incomplete formation of an anticorrosive film on iron or aluminum. It does not improve, but there exists a possibility of lowering the other physical property of a heating water composition on the contrary.

The stabilizer acts to secure the stability of the corrosion inhibitors added to the heating water composition, and specifically, sodium molybdate is preferably used.

The addition amount of the stabilizer is preferably 0.01 to 1.0 parts by weight based on 100 parts by weight of the purified glycol aqueous solution. When the amount of the stabilizer added is less than the above-limited range, the added amount is small and a sufficient anticorrosive effect cannot be expected. There exists a possibility of reducing the other physical property of a heating water composition.

When the heating water composition for boiler is used for a long period of time, the bubbles generated by various causes promote the corrosion of the pipe. As an additive to increase the , it is preferable to use a silicone oil or silicone emulsion, or a mixture thereof.

It is preferable to add 0.01 to 0.1 parts by weight of the antifoaming agent based on 100 parts by weight of the purified glycol aqueous solution. When the amount of the antifoaming agent is added below the above-limited range, there is a fear that the bubbles generated in the heating water composition cannot be sufficiently removed. The amount of bubble removal generated in the heating water composition is not proportional, and there is a risk of lowering other physical properties of the heating water composition.

Therefore, in the present invention, when the pipe is oxidized and corroded by the bubbles generated in the heating water composition for boiler, the heat transfer efficiency is lowered. heightening effect.

Hereinafter, the configuration of the heating water composition according to the present invention will be described in more detail through the following examples. However, the following examples are only presented to understand the content of the present invention and should not be construed as limiting the scope of the present invention to these examples.

1. Energy saving type heating water Preparation of the composition

According to the contents of Table 1 below, purified ethylene glycol and purified water were first mixed to prepare ethylene glycol aqueous solutions of Examples 1 to 3 and Comparative Examples 1 to 3.

ingredient Mixing composition ratio (wt%) Example comparative example One 2 3 One 2 3 ethylene glycol 70 75 80 70 75 80 Purified water 20 25 20 30 25 20

And the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were prepared by adding the compounds as described in Table 2 below to the ethylene glycol aqueous solution prepared according to the composition ratio of Table 1 above.

For reference, Comparative Examples 1 to 3 compared to Examples 1 to 3 in [Table 2] below were applied to the heating water composition of Patent Document 4, a patent registered by the present applicant.

ingredient Mixing composition ratio (parts by weight) Example comparative example One 2 3 One 2 3 Ethylene glycol aqueous solution 100 100 100 100 100 100 benzimidazole 0.05 0.1 2.0 - - - toritriazole 0.5 1.0 2.0 1.0 1.5 2.0 Soda benzoate 0.1 0.7 2.0 2.5 2.5 2.5 Sodium Molybdate 0.01 0.5 1.0 0.3 0.5 1.0 sodium nitrate - - - 0.5 1.0 1.5 2-ethylhexanoic acid - - - 1.0 1.5 2.0 sebacic acid - - - 1.0 1.5 2.0 p-t-butylbenzoic acid - - - 0.5 1.0 1.5 cyclohexylamine 0.1 1.0 2.0 - - - silicone oil 0.01 0.05 0.1 - - -

2. Test method of heating water composition

According to the test method below, the results of the heating tests for the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 are the same as the contents of [Table 3] below, and the results of the performance tests for corrosion and freezing point are as follows It is the same as the contents of [Table 4].

(1) Heating test

The test method for the time required to heat up to 100°C is as follows.

Using the test device specified in KS M 2141 (2015.07.31. revision), insert the thermometer into the side tube of the flask, seal the gap with a rubber tube, and install so that the lower end of the thermometer is at a height of about 6.5 mm from the center of the bottom of the flask, In a flask, 60 ml of each of the samples of the heating water composition of Examples 1 to 3 and Comparative Examples 1 to 3 and 3 boiling stones were placed. As a heat source, a heat-resistant plate with a hole of 32-38 mm in diameter is installed on the top, and a flask is installed so that it can be heated through the hole of the heat-resistant plate. Cool the cooler by flowing water of 28°C or lower, and the temperature rise of the cooling water during measurement should be within 2°C. When the power of the heat-resistant plate was turned on, the stopwatch was started and the time to reach 100°C was measured. The measurement results in [Table 3] below were tested twice for each sample, and the average value was measured.

(2) Corrosion test

Corrosion test was performed as follows by the method specified in KS M 2142. First, aluminum, cast iron, steel, brass, solder, and copper test pieces were prepared, and mixed water was prepared in which sodium sulfate 148 mg, sodium chloride 165 mg, and sodium hydrogen carbonate 138 mg were dissolved in 1 liter of water, Examples 1 to 3 And the test pieces were immersed in a test solution in which the heating water composition of Comparative Examples 1 to 3 was diluted to 30% by volume with mixed water. It is maintained for 336 hours (14 days) at the test solution temperature of 88±2℃ while injecting dry air at a rate of 100±10ml/min. The amount of liquid was checked daily, the amount of evaporation loss of the liquid was supplemented with water, and after the test was completed, the test piece was treated with each treatment liquid and dried to measure the change in weight of the test piece up to 0.1 mg. The amount of change in weight was calculated by Equation (1) below. Each test piece was tested twice, and the average value was measured.

(1)

(One)

where C: change in weight (mg/cm2)

W': weight of the test piece after the test (mg)

W: Weight of test piece before test (mg)

S: Total surface area of the test piece before the test (cm2)

(3) Freezing point test

30% by volume and 50% by volume of the test solution were prepared from the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3, 100ml each of the test solution was put into a cooling tube in a freezing point measuring device, and a chopstick and a thermometer were corkscrewed. B. Install it using a rubber stopper, and place the bottom end of the thermometer in the center of the test solution. Put the cooling tube in the cooling solution made with acetone or methanol and dry ice, and start cooling so that the liquid level of the test solution is about 10 mm lower than the liquid level of the cooling solution, and at the same time, turn the chopstick up and down at a rate of 60 to 80 times per minute. stir with The temperature is recorded every minute, and the temperature at which the temperatures become parallel is used as the freezing point. The test was performed twice to determine the average value.

(4) pH drop prevention performance test

Evaluation of pH fall prevention performance was performed by the accelerated deterioration test. In this test, the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were each diluted by mixing with water to 30% by volume, and then sodium hydroxide was added to the diluted heating water composition to adjust the pH to 8.0. did. Then, 200 ml of the diluted heating water composition was placed in a 1 liter pressure autoclave, and the pH was measured after heating at 110° C. for 500 hours.

3. Evaluation of heating water composition

As a result of testing the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 according to 2 (test method of heating water composition), the heating time, corrosive performance, freezing point temperature and pH buffering performance are as described below. .

As a result of the heating test, as shown in [Table 3] below, the heating water compositions of Examples 1 to 3 and the heating water compositions of Comparative Examples 1 to 3 according to the present invention showed a longer heating time to 100° C. compared to tap water. It was confirmed that it was shortened. And it was confirmed that the heating time required for heating the heating water compositions of Examples 1 to 3 to 100° C. was further reduced compared to the heating water compositions of Comparative Examples 1 to 3.

Therefore, the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 are purified ethylene glycol aqueous solution composed of 70 to 80% by weight of purified ethylene glycol and 20 to 30% by weight of water. It can be seen that the heat efficiency is good as much as the time required for heating is shortened, so the energy used is reduced.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 tap water heating time 8 minutes 51 seconds 8 minutes 37 seconds 8 minutes 21 seconds 8 minutes 48 seconds 8 minutes 40 seconds 8 minutes 17 seconds 10 minutes 21 seconds

As a result of the corrosion test, according to [Table 4] below, the corrosion test results showed that the heating water compositions of Examples 1 to 3 and Comparative Examples 3 had superior corrosion resistance performance compared to the heating water compositions of Comparative Examples 1 to 3.

The results shown in [Table 4] below show that Examples 1 to 3, unlike Comparative Examples 1 to 3, exhibited a buffering action in which the added imidazole-based corrosion inhibitor, benzimidazole, inhibits the decrease in the pH of the heating water composition. By doing so, the pH of the heating water composition is not lowered, so that corrosion inhibitors such as totriazole and sodium benzoate properly exhibit corrosion inhibitory performance, whereas the heating water compositions of Comparative Examples 1 to 3 lower the pH, and the corrosion inhibitors inhibit metal corrosion It is presumed that this is due to the reduced ability.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 corrosion resistance

weight loss
(mg/cm2) aluminum 0.05 0.05 0.04 0.06 0.06 0.06 cast iron 0.04 0.04 0.03 0.05 0.05 0.04 steel 0.02 0.02 0.02 0.03 0.03 0.03 brass 0.03 0.02 0.02 0.04 0.04 0.04 pewter 0.03 0.03 0.03 0.05 0.04 0.04 Copper 0.02 0.02 0.02 0.04 0.04 0.03 Freezing point (℃) < -60 < -60 < -60 < -60 < -60 < -60

The freezing point test results are as shown in Table 4 above, the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 are purified ethylene glycol aqueous solution consisting of 70 to 80% by weight of purified ethylene glycol and 20 to 30% by weight of water. As a result, it was confirmed that all freezing points were below -60 °C.

Therefore, all of the heating water compositions of Examples 1 to 3 and Comparative Examples 1 to 3 have a freezing point of −60° C. or less, so the freezing point of the heating water is very low, Therefore, it was confirmed that it was possible to sufficiently prevent freezing of the boiler piping and internal combustion engine.

And as a result of the accelerated degradation test, as shown in Table 5 below, Examples 1 to 3 showed a pH value of 7 or more after the test, and Comparative Examples 1 to 3 showed a pH value lower than 7 after the test. It can be seen that Examples 1 to 3 are superior to Comparative Examples 1 to 3 in preventing pH decrease.

division Example comparative example One 2 3 One 2 3 heating water pH 7.1 7.3 7.5 6.2 6.3 6.1

As a result of evaluating the heating water composition of Examples 1 to 3, which is a heating water composition according to the present invention, and Comparative Examples 1 to 3, compared thereto, 70 to 80% by weight of purified ethylene glycol and 20 to 30% by weight of water % of the boiling time and freezing point performance were evaluated at almost the same level as the purified ethylene glycol aqueous solution consisting of Unlike the heating water composition, it was found that the performance of corrosion resistance was excellent by using benzimidazole, an imidazole-based corrosion inhibitor.

As described above, although the heating water composition for an energy-saving boiler according to a preferred embodiment of the present invention has been described, this is merely an example and various changes and modifications can be made without departing from the technical spirit of the present invention. It will be well understood by those skilled in the art that this is possible.

Claims (4)

In the heating water composition for an energy-saving boiler whose main components are purified glycol and water,
Based on 100 parts by weight of the purified glycol aqueous solution, 0.05 to 2.0 parts by weight of an imidazole-based corrosion inhibitor, 0.5 to 2.0 parts by weight of a triazole-based corrosion inhibitor, 0.1 to 2.0 parts by weight of a benzoate, 0.1 to 2.0 parts by weight of a pH adjuster, 0.01 to a stabilizer Heating water composition for an energy-saving boiler, characterized in that it consists of 1.0 parts by weight and 0.01 to 0.1 parts by weight of an antifoaming agent.
The method of claim 1,
The purified glycol aqueous solution consists of 70 to 80% by weight of purified glycol and 20 to 30% by weight of water,
The purified glycol is a heating water composition for an energy-saving boiler, characterized in that purified ethylene glycol or purified propylene glycol.
According to claim 1,
The imidazole-based corrosion inhibitor is selected from 1-methylimidazole, 1-ethylimidazole, 1-phenylimidazole, or benzimidazole, or a mixture thereof. .
The method of claim 1,
The triazole-based corrosion inhibitor is 1,2,3 benzotriazole or 1 to 3 parts by weight, an energy saving heating water composition for a boiler, characterized in that selected from totriazole or a mixture thereof.