阅读说明：本技术 一种用于锅炉的水质稳定剂 (Water quality stabilizer for boiler ) 是由 黄庆基 贾金成 黄秀辉 于 2021-06-30 设计创作，主要内容包括：本发明提供了所述水质稳定剂包括15-35wt％的螯合剂、2-3wt％阻垢剂、0.2-0.5wt％缓蚀剂、0-0.5wt％分散剂和0-0.5wt％增效剂,余量为水；所述螯合剂包括乙二胺、乙二胺四乙酸二钠；可有效降低炉水的含盐量和电导率；使得锅炉水处理系统不需要连续排水,仅仅采用定期排水就可以稳定维持,该水质稳定剂用于锅炉水处理,不但可以减少水汽损失,蒸汽与水的比值提高1.3％,使得吨煤产汽量增加,同时又可以提升蒸汽品质,降低蒸汽杂质,进而提高了发电机组带负荷的能力、机组热效率、延长检修周期,保证了锅炉机组的安全经济运行。(The invention provides a water quality stabilizer which comprises 15-35 wt% of chelating agent, 2-3 wt% of scale inhibitor, 0.2-0.5 wt% of corrosion inhibitor, 0-0.5 wt% of dispersant, 0-0.5 wt% of synergist and the balance of water; the chelating agent comprises ethylenediamine and disodium ethylene diamine tetraacetate; the salt content and the conductivity of the furnace water can be effectively reduced; the water quality stabilizer is used for boiler water treatment, not only can the water vapor loss be reduced, but also the ratio of steam to water is improved by 1.3%, so that the steam yield per ton of coal is increased, the steam quality can be improved, steam impurities are reduced, the load capacity of a generator set is improved, the heat efficiency of the generator set is improved, the overhaul period is prolonged, and the safe and economic operation of the boiler set is ensured.)

1. A water quality stabilizer for a boiler is characterized by comprising 15-35 wt% of chelating agent, 2-3 wt% of scale inhibitor, 0.2-0.5 wt% of corrosion inhibitor, 0-0.5 wt% of dispersant, 0-0.5 wt% of synergist and the balance of water; the chelating agent comprises ethylenediamine and disodium ethylene diamine tetraacetate.

2. The water quality stabilizer according to claim 1, wherein the mass ratio of ethylenediamine to disodium ethylenediamine tetraacetate is 2-5: 3-4.

3. The water quality stabilizer according to claim 1, wherein the scale inhibitor is a polyphosphate.

4. A water quality stabilizer according to claim 1, wherein the corrosion inhibitor is hexamethylenetetramine.

5. The water quality stabilizer according to claim 1, wherein the boiler supplies boiler steam with a pressure of 3.8-5.8Mpa to a papermaking process.

6. The water quality stabilizer according to claim 1, wherein the amount of the water quality stabilizer is 10-20kg/T boiler water.

Technical Field

The invention relates to the field of papermaking, in particular to a water quality stabilizer for a boiler.

Background

The papermaking industry uses a large volume of steam and therefore many paper mills use large boiler systems to cyclically produce papermaking steam. In order to prevent corrosion and scaling of a thermodynamic system of a boiler; according to the GB/T12145-2016 specification requirement, the boiler water is treated by adding a solid alkalizer (phosphate, sodium hydroxide and the like are added), and the boiler water quality control standard with the steam pressure of 3.8-5.8MPa is as follows: 5-15mg/L of phosphate, 9.0-11.0 of pH and corresponding salt content of furnace water (conductivity 50-120 mu s/cm). However, the salt content (conductivity) of the furnace water is also high, so that impurities (sodium ions, iron ions, silicon dioxide and the like) carried by steam are also often high, and the method is a negative factor for safe and economic operation of a steam turbine generator unit. In order to ensure better steam quality, the salt content of the boiler water must be reduced through continuous pollution discharge and periodic pollution discharge, so that the water vapor loss of the boiler is caused to a certain extent, and the economic operation of a generator set is not facilitated.

Disclosure of Invention

Therefore, the water quality stabilizer for reducing the salt content of the boiler water, reducing the pollution discharge rate of the boiler and reducing the water vapor loss of the boiler is provided.

Firstly, the inventor provides a water quality stabilizer for a boiler, wherein the water quality stabilizer comprises 15-35 wt% of chelating agent, 2-3 wt% of scale inhibitor, 0.2-0.5 wt% of corrosion inhibitor, 0-0.5 wt% of dispersant, 0-0.5 wt% of synergist and the balance of water; the chelating agent comprises ethylenediamine and disodium ethylene diamine tetraacetate.

The ethylenediamine and the ethylene diamine tetraacetic acid can still form a stable chelate with metal ions under the conditions of high temperature and high pressure generated by steam. The generated chelate can be deposited at the bottom of the boiler during the operation of the boiler and is removed through periodic pollution discharge.

Furthermore, the mass ratio of the ethylenediamine to the ethylene diamine tetraacetic acid is 2-5: 3-4.

Further, the scale inhibitor is polyphosphate.

Further, the corrosion inhibitor is hexamethylenetetramine.

Further, the boiler provides boiler steam with the pressure of 3.8-5.8Mpa for the papermaking process.

Furthermore, the amount of the water quality stabilizer is 10-20kg/T boiler water.

Furthermore, after the water quality stabilizer is added into boiler water, the boiler adopts a regular drainage mode to control the salt content.

Different from the prior art, the technical scheme provides the water quality stabilizer for boiler water treatment, which can effectively reduce the salt content and the conductivity of boiler water; the water quality stabilizer is used for boiler water treatment, not only can the water vapor loss be reduced, but also the ratio of steam to water is improved by 1.3%, so that the steam yield per ton of coal is increased, the steam quality can be improved, steam impurities are reduced, the load capacity of a generator set is improved, the heat efficiency of the generator set is improved, the overhaul period is prolonged, and the safe and economic operation of the boiler set is ensured.

Drawings

FIG. 1 is a graph showing the comparison of the results of the measurement of the salt content in the furnace water in the examples.

FIG. 2 is a graph comparing the results of measuring the sodium ion content in the steam of the examples.

Detailed Description

To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

In this embodiment, ethylenediamine, EDTA, and metal ions form a complex: the ethylenediamine reacts with copper salt, manganese salt, cobalt salt and the like to generate corresponding complex salt. Ethylenediamine and heavy metal ions can form stable complexes. EDA and Cd can be used in metal quantitative analysis²⁺、Co²⁺、Cu²⁺Or Hg²⁺Forming a complex. Macrocyclic rings of 10 to 18 atoms with 2n nitrogen atoms which can be prepared with ethylenediamine form polydentate complexes with metal ions, which complexes are used in catalytic reactions for the preparation of specific products. The chromium (+2) salt reacts with EDTA to easily prepare the reducing agent, and the EDTA can greatly improve the Cr content²⁺The reducing power of (a) can reduce a primary alkyl halide to an alkane and an aryl bromide or iodide to an aromatic hydrocarbon.

Disodium ethylene diamine tetraacetate can be dissolved in water and is extremely insoluble in ethanol, and can chelate metal ions in the solution. Preventing discoloration, deterioration, turbidity and oxidation loss of vitamin C caused by metal, and improving oxidation resistance of oil (trace metal such as iron and copper in oil can promote oxidation of oil).

Example 1 a water quality stabilizer for a boiler:

the water quality stabilizer comprises 15-35 wt% of chelating agent, 2-3 wt% of scale inhibitor (polyphosphate), 0.2-0.5 wt% of corrosion inhibitor (hexamethylenetetramine), 0.5 wt% of dispersant and 0.5 wt% of synergist, and the balance of water; the chelating agent comprises ethylenediamine and disodium ethylene diamine tetraacetate. The mass ratio of the ethylenediamine to the disodium ethylene diamine tetraacetate is 4: 4. The boiler provides boiler steam with the pressure of 5.5Mpa and the steam temperature of 270 ℃ for the papermaking process; the amount of the water quality stabilizer is 15kg/T boiler water.

After the boiler uses the new water quality stabilizer, the pollution discharge control fully closes the continuous drainage gate, and the salt content of the boiler water is controlled and adjusted only by the periodic drainage gate. Through application tests, the water quality stabilizer is used for replacing the traditional solid alkalizer for treating the boiler water, the salt content of the boiler water can be kept at a lower level, the steam quality is improved, the water vapor loss caused by boiler pollution discharge can be reduced, and the method is an effective method for saving energy and reducing consumption of a unit.

FIG. 1 is a graph showing the comparison of the results of the measurement of the salt content in the furnace water in the examples. FIG. 2 is a graph comparing the results of measuring the sodium ion content in the steam of the examples. As can be seen from fig. 1-2, both the salt content of the furnace water and the sodium ion content of the steam are reduced.

The water quality stabilizer is treated by a solid alkalizer before use, the average steam-water ratio is 1.030, and the steam-water ratio after use is 1.043, which is improved by 0.013 (detailed in Table 1).

TABLE 1 steam-Water ratio test record

The temperature of the boiler continuous exhaust steam is 270 ℃, the pressure is 5.5MPa, the enthalpy is 2788.35KJ/Kg, and the heat value of 1 ton of steam is equivalent to 95Kg of standard coal.

③ the raw coal (low heat value 5000Kcal/Kg) is charged to the plant at 660 yuan per ton, and the converted standard coal price is 924 yuan

The/ton is 0.924 yuan/Kg, and the value of the continuous boiler exhaust steam is as follows: 95 × 0.924 ═ 87.78 yuan/ton.

Fourthly, the installation and installation of the boiler of the thermal power plant are (130 multiplied by 3+75 multiplied by 1) t/h, the actual average load of the boiler is 122t/h, the annual operation time is 320 days, the water vapor price is 87.78 yuan/t, and the cost of the desalted water is 6 yuan/t:

the economic benefits that can be brought by 1 furnace every year are: 122 × 320 × 24 × 0.013 × (87.78+6) ═ 1142285 yuan. The 3-furnace annual benefit is (consider a 75t boiler operating for 160 days per year): 1142285 x [ 2.5+ (75/130) x 0.5 ] ═ 329505 yuan.

The water quality stabilizer is used for boiler water treatment, can reduce water vapor loss, increase steam yield per ton of coal, and improve steam quality, thereby ensuring safe and economic operation of a unit (improving the load capacity of a power generation unit, the heat efficiency of the unit, prolonging the maintenance period and the like).

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.

It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.