Cleaning agent for flue dust scale on surface of gas heat exchanger of gas desulfurization system and preparation method thereof

Abstract

The invention discloses a cleaning agent for flue dust scale on the surface of a gas heat exchanger of a gas desulfurization system and a preparation method thereof. The cleaning agent is characterized by comprising the following components in percentage by mass: 5 to 25 percent of main cleaning agent, 3 to 15 percent of auxiliary cleaning agent, 2 to 10 percent of release agent, 2 to 8 percent of corrosion inhibitor, and the balance water, wherein the main cleaning agent is one or two of nitric acid, hydrochloric acid and sulfuric acid; the auxiliary cleaning agent is more than one of methanoic acid, acetic acid, ethylene diamine tetraacetic acid, sulfamic acid, glycollic acid, oxalic acid and hydroxyethylidene diphosphonic acid; the release agent is one of dodecyl dimethyl benzyl ammonium bromide, dodecyl dimethyl benzyl ammonium chloride and distearyl dimethyl ammonium chloride; and the corrosion inhibitor is pickling inhibitor. The cleaning agent can realize online cleaning at normal temperature, complete scale removal, short cleaning time, lower cleaning cost and no corrosion to enamel on the surface of a heat exchange element.

Description

technical field

[0001] The invention relates to a cleaning agent, in particular to a cleaning agent for cleaning smoke and dust fouling on the surface of a gas-gas heat exchanger arranged in a limestone-gypsum desulfurization system in a large-scale electric coal-fired unit. Background technique

[0002] Coal-fired power generation is still one of the main methods of power production in my country. At present, more than 90% of the limestone-gypsum desulfurization systems in my country's large-scale power coal-fired units are equipped with gas-gas heat exchangers (GGH for short). Whether the high-cost equipment outside the system is normal or not is related to the stable operation of the flue gas desulfurization system. In the desulfurization system that has been put into operation, after a period of use, problems such as serious fouling and blockage of GGH, poor heat transfer efficiency, and pressure difference far higher than the design value will occur, and the desulfurizat...

Examples

Embodiment 1

[0022] In the first step, the raw materials are configured according to the following mass percentage components:

[0023] Cleaning main agent 5%, adopting the nitric acid that mass percentage concentration is 68%;

[0024] 3% of cleaning aids, adopting mass percent concentration of 90% formic acid;

[0025] Stripping agent 2%, using dodecyl dimethyl benzyl ammonium bromide;

[0026] Corrosion inhibitor 2%, adopt the multifunctional pickling corrosion inhibitor (Lan826) produced by Lanzhou Tianhua Chemical Research Institute;

[0027] The remainder is water;

[0028] In the second step, the raw materials prepared in the first step are evenly stirred under normal temperature and pressure to obtain a cleaning agent for cleaning smoke and dust on the surface of the flue gas heat exchanger of the desulfurization system.

Embodiment 2

[0030] Referring to the first step of the example, prepare the soot fouling cleaning agent on the surface of the flue gas heat exchanger of the desulfurization system according to the following mass percentage composition ratio:

[0031] 15% of the main cleaning agent, using hydrochloric acid with a mass percentage concentration of 31%;

[0032] 10% of cleaning aids, using 99% acetic acid in mass percent concentration;

[0033] Stripping agent 8%, using dodecyl dimethyl benzyl ammonium chloride;

[0034] Corrosion inhibitor 5%, adopt the multifunctional pickling corrosion inhibitor (IS139) produced by Shaanxi Petrochemical Research and Design Institute;

[0035] The balance is water.

Embodiment 3

[0037] Referring to the first step of the example, prepare the soot fouling cleaning agent on the surface of the flue gas heat exchanger of the desulfurization system according to the following mass percentage composition ratio:

[0038] The main cleaning agent is 25%, and the mass percent concentration is 98% sulfuric acid;

[0039] 15% cleaning aid, using ethylenediaminetetraacetic acid with a mass percentage concentration of 99%;

[0040] 10% stripping agent, using dimethyl dioctadecyl ammonium chloride;

[0041] Corrosion inhibitor 8%, adopt hydrochloric acid pickling corrosion inhibitor (IS129) produced by Shaanxi Petrochemical Research and Design Institute;

[0042] The balance is water.

technical field

[0001] The invention relates to a cleaning agent, in particular to a cleaning agent for cleaning smoke and dust fouling on the surface of a gas-gas heat exchanger arranged in a limestone-gypsum desulfurization system in a large-scale electric coal-fired unit. Background technique

[0002] Coal-fired power generation is still one of the main methods of power production in my country. At present, more than 90% of the limestone-gypsum desulfurization systems in my country's large-scale power coal-fired units are equipped with gas-gas heat exchangers (GGH for short). Whether the high-cost equipment outside the system is normal or not is related to the stable operation of the flue gas desulfurization system. In the desulfurization system that has been put into operation, after a period of use, problems such as serious fouling and blockage of GGH, poor heat transfer efficiency, and pressure difference far higher than the design value will occur, and the desulfurizat...

Examples

Embodiment 1

[0022] In the first step, the raw materials are configured according to the following mass percentage components:

[0023] Cleaning main agent 5%, adopting the nitric acid that mass percentage concentration is 68%;

[0024] 3% of cleaning aids, adopting mass percent concentration of 90% formic acid;

[0025] Stripping agent 2%, using dodecyl dimethyl benzyl ammonium bromide;

[0026] Corrosion inhibitor 2%, adopt the multifunctional pickling corrosion inhibitor (Lan826) produced by Lanzhou Tianhua Chemical Research Institute;

[0027] The remainder is water;

[0028] In the second step, the raw materials prepared in the first step are evenly stirred under normal temperature and pressure to obtain a cleaning agent for cleaning smoke and dust on the surface of the flue gas heat exchanger of the desulfurization system.

Embodiment 2

[0030] Referring to the first step of the example, prepare the soot fouling cleaning agent on the surface of the flue gas heat exchanger of the desulfurization system according to the following mass percentage composition ratio:

[0031] 15% of the main cleaning agent, using hydrochloric acid with a mass percentage concentration of 31%;

[0032] 10% of cleaning aids, using 99% acetic acid in mass percent concentration;

[0033] Stripping agent 8%, using dodecyl dimethyl benzyl ammonium chloride;

[0034] Corrosion inhibitor 5%, adopt the multifunctional pickling corrosion inhibitor (IS139) produced by Shaanxi Petrochemical Research and Design Institute;

[0035] The balance is water.

Embodiment 3

[0037] Referring to the first step of the example, prepare the soot fouling cleaning agent on the surface of the flue gas heat exchanger of the desulfurization system according to the following mass percentage composition ratio:

[0038] The main cleaning agent is 25%, and the mass percent concentration is 98% sulfuric acid;

[0039] 15% cleaning aid, using ethylenediaminetetraacetic acid with a mass percentage concentration of 99%;

[0040] 10% stripping agent, using dimethyl dioctadecyl ammonium chloride;

[0041] Corrosion inhibitor 8%, adopt hydrochloric acid pickling corrosion inhibitor (IS129) produced by Shaanxi Petrochemical Research and Design Institute;

[0042] The balance is water.