Quick plugging method for condenser based on sulfydryl-isocyanate click reaction

Abstract

The embodiment of the invention provides a quick plugging method for a condenser based on a sulfydryl-isocyanate click reaction, which comprises the following steps: firstly, preparing a mixture containing sulfydryl and an isocyanate group, and adding a catalyst to obtain a plugging agent for plugging heat exchange of the condenser. When leaking stoppage is needed, the leaking stoppage agent is added into a condenser heat exchange pipe, and the quick leaking stoppage effect can be achieved under the dual catalytic action of the catalyst and water vapor in the heat exchange pipe. According to the rapid leaking stoppage method, the leaking stoppage agent is easy to prepare, the leaking stoppage process is rapid, the rapid leaking stoppage method can adapt to various heat exchange tube sizes and different surface cleanliness, and due to existence of water vapor in the heat exchange tubes, the mixture curing leaking stoppage process can be accelerated. According to the method, leaking stoppage is carried out based on the click chemical reaction, the defects of a traditional physical leaking stoppage technology are overcome, and the leaking stoppage working efficiency and the leaking stoppage effect are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of condenser leakage treatment, and in particular relates to a condenser rapid leakage plugging method based on mercapto-isocyanate click reaction. Background Art

[0002] As one of the important equipment in the steam system of power generators, condensers are widely used in thermal power units and nuclear power units, and their stable operation is crucial. However, leakage of condenser heat exchange tubes occurs from time to time. Since the cooling water outside the condenser heat exchange tubes is usually of poor quality, especially for seashore power plants that use seawater direct cooling, the cooling water is seawater, and the salt content of seawater is much higher than that of fresh water, among which Na + and Cl - The content of Na + and Cl - Leakage into the water vapor system will cause a sudden drop in the water vapor quality of the unit, resulting in serious consequences such as corrosion and salt accumulation of the turbine, corrosion and scaling of thermal equipment, etc.

[0003] Traditional methods for dealing with condenser leakage include adding sawdust and plugging. Adding sawdust has a certain effect on small leaks in running units, but when the leakage aperture is large, it is often unable to effectively plug the leak. Plug plugging uses copper or rubber as raw materials and is prepared according to the size of the condenser tube. In order to ensure the plugging effect, there are high requirements for the matching degree of the plug size and the condenser tube, the material and service life of the plug. If the plug corrodes and leaks, the plug size is not suitable, or there are foreign objects in the condenser tube wall during the plugging process, the plugging effect will be reduced, and it will not be possible to ensure the complete isolation of the leaking condenser tube, which will also cause serious consequences such as corrosion and salt accumulation of the turbine and corrosion and scaling of thermal equipment.

[0004] Therefore, developing a condenser rapid plugging method that is adapted to the size of the condenser heat exchange tube and has no requirements for the cleanliness of the inner wall of the heat exchange tube will help improve the plugging effect and thus ensure the safe operation of the unit. Summary of the invention

[0005] The embodiment of the present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a condenser rapid plugging method based on mercapto-isocyanate click reaction.

[0006] An embodiment of the present invention provides a condenser rapid plugging method based on a mercapto-isocyanate click reaction, the method comprising:

[0007] The compound containing a mercapto group and the compound containing an isocyanate group are mixed at room temperature in a molar ratio of the mercapto group to the isocyanate group of 1:1 to obtain a leak-proof agent;

[0008] Mix the plugging agent and the catalyst evenly;

[0009] The plugging agent mixed with the catalyst is filled into the leaking condenser heat exchange tube, and the plugging agent is waited for to solidify by itself, so that the quick plugging of the condenser heat exchange tube can be completed.

[0010] In some possible embodiments, the compound containing a thiol group is a multifunctional thiol compound.

[0011] In some possible embodiments, the thiol-containing compound includes trimethylolpropane trimercaptopropionate, pentaerythritol tetramercaptopropionate, or triphenylene-2,3,6,7,10,11-hexathiol.

[0012] In some possible embodiments, the isocyanate-containing compound is a multifunctional isocyanate compound.

[0013] In some possible embodiments, the isocyanate-containing compound includes hexamethylene diisocyanate, isophorone diisocyanate, or toluene-2,4-diisocyanate.

[0014] In some possible embodiments, the catalyst is a catalyst for mercapto-isocyanate reaction.

[0015] In some possible embodiments, the catalyst includes dibutyltin diacetate, triethylamine, or an imidazole compound.

[0016] In some possible embodiments, the mass ratio of the plugging agent to the catalyst should be 0.1% to 0.5%.

[0017] In some possible embodiments, the plugging agent mixed with the catalyst is filled into the leaking condenser heat exchange tube, and the plugging agent is waited for self-solidification to complete the rapid plugging of the condenser heat exchange tube, including:

[0018] The plugging agent mixed with the catalyst is filled into the leaking condenser heat exchange tube. Under the joint catalysis of the catalyst and the moisture in the heat exchange tube, a mercapto-isocyanate click reaction occurs, which solidifies to form a polymer resin material, thereby achieving rapid plugging of the condenser.

[0019] In some possible embodiments, the curing and plugging time is controlled within 5 to 30 minutes, and with the contact with water, the plugging agent will further solidify deeply and form hydrogen bonds with the heat exchange tube wall, thereby strengthening the bonding strength with the tube wall to enhance the plugging effect.

[0020] Compared with the prior art, the present invention provides a condenser rapid plugging method based on mercapto-isocyanate click reaction, which has the following beneficial effects:

[0021] First, since the mercapto-isocyanate reaction rate is very fast, the condenser can be quickly plugged. Secondly, the humidity in the heat exchange tube is generally high, and moisture will accelerate the mercapto-isocyanate reaction, further accelerating the plugging efficiency. In addition, the polymer resin formed after the mercapto-isocyanate is cured can form a hydrogen bond with the condenser tube wall, strengthening the bonding effect between the plugging agent and the heat exchange tube, thereby strengthening the plugging effect and avoiding the leakage of circulating water and contamination of condensed water due to lax plugging. Finally, since the plugging agent is a mixture of compounds with a certain viscosity, the plugging effect can be achieved for condenser heat exchange tubes of different sizes. This process does not require the cleanliness of the tube wall of the condenser heat exchange tube, and is applicable to various condenser tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a scanning electron microscope image of a polymer resin formed after the mercapto-isocyanate plugging agent according to an embodiment of the present invention is cured. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0025] Unless otherwise specifically stated, the relative arrangement of the components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship, and the techniques, methods and devices known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and devices shown should be considered as part of the authorized specification. In all examples shown and discussed here, any specific other examples may have different values. It should be noted that similar symbols and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0026] In the description of the embodiments of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in the embodiments of the present invention and the features of the different embodiments or examples, without contradiction.

[0027] The embodiment of the present invention provides a method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction, the method comprising the following steps:

[0028] Step 1: Mix a compound containing a mercapto group and a compound containing an isocyanate group at a molar ratio of 1:1 between the mercapto group and the isocyanate group at room temperature to obtain a plugging agent.

[0029] Specifically, in this step, the thiol-containing compound is a multifunctional thiol compound. For example, the thiol-containing compound includes but is not limited to trimethylolpropane trimercaptopropionate, pentaerythritol tetramercaptopropionate, or triphenylene-2,3,6,7,10,11-hexathiol, etc. The isocyanate-containing compound is a multifunctional isocyanate compound, for example, the isocyanate-containing compound includes but is not limited to 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or toluene-2,4-diisocyanate, etc.

[0030] Step 2: Mix the plugging agent and catalyst evenly.

[0031] Specifically, in this step, the catalyst may be a catalyst for mercapto-isocyanate reaction, for example, the catalyst includes but is not limited to dibutyltin diacetate, triethylamine, or imidazole compounds.

[0032] In some embodiments, the mass ratio of the plugging agent to the catalyst is 0.1% to 0.5%.

[0033] Step 3: Fill the plugging agent mixed with the catalyst into the leaking condenser heat exchange tube, and wait for the plugging agent to solidify by itself, so as to complete the rapid plugging of the condenser heat exchange tube.

[0034] Specifically, in this step, a plugging agent mixed with a catalyst is loaded into the leaking condenser heat exchange tube, and under the joint catalysis of the catalyst and the moisture in the heat exchange tube, a mercapto-isocyanate click reaction occurs, which solidifies to form a polymer resin material, thereby achieving rapid plugging of the condenser.

[0035] In some embodiments, the curing and plugging time is controlled within 5 to 30 minutes, and with the contact with water, the plugging agent will further solidify and form hydrogen bonds with the heat exchange tube wall, thereby strengthening the bonding strength with the tube wall to enhance the plugging effect.

[0036] In the condenser rapid plugging method based on the mercapto-isocyanate click reaction of the embodiment of the present invention, the polymer resin formed after the mercapto-isocyanate plugging agent is cured is shown in the scanning electron microscope image. Figure 1 shown.

[0037] Compared with the prior art, the condenser rapid plugging method based on the mercapto-isocyanate click reaction of the embodiment of the present invention has the following beneficial effects:

[0038] First, since the mercapto-isocyanate reaction rate is very fast, the condenser can be quickly plugged. Secondly, the humidity in the heat exchange tube is generally high, and moisture will accelerate the mercapto-isocyanate reaction, further accelerating the plugging efficiency. In addition, the polymer resin formed after the mercapto-isocyanate is cured can form a hydrogen bond with the condenser tube wall, strengthening the bonding effect between the plugging agent and the heat exchange tube, thereby strengthening the plugging effect and avoiding the leakage of circulating water and contamination of condensed water due to lax plugging. Finally, since the plugging agent is a mixture of compounds with a certain viscosity, the plugging effect can be achieved for condenser heat exchange tubes of different sizes. This process does not require the cleanliness of the tube wall of the condenser heat exchange tube, and is applicable to various condenser tubes.

[0039] The technical principle of the present invention is described below.

[0040] Click reactions have the characteristics of simple reaction conditions (no solvent or water required), fast reaction rate, high reaction yield, few by-products, and environmental friendliness. Typical click reactions are Cu-catalyzed azide-alkyne reactions and Diels-Alder reactions between olefins. In addition, the thiol-isocyanate reaction has also become a representative of click chemistry due to its high reactivity, fast reaction rate, and low reaction by-products.

[0041] The mercapto-isocyanate click reaction is a nucleophilic addition reaction, and its reaction principle is as follows.

[0042]

[0043] In the Michael addition reaction, under the action of the catalyst, the thiol becomes a sulfur anion with strong nucleophilicity, and the carbonyl group of the isocyanate is polarized and exhibits electron-deficient characteristics, which facilitates the attack of the nucleophilic group. The reaction generates an anion intermediate, which then transfers electrons to the thiol and captures the hydrogen atom of the thiol, thereby generating polythiourethane.

[0044] Usually, under the action of a catalyst, the reaction only takes a few minutes to complete. Therefore, it is fast and convenient to use it as a plugging agent for condenser heat exchange tubes.

[0045] Now, the present invention will be further described with reference to the embodiments:

[0046] Embodiment 1:

[0047] Weigh 10g of trimethylolpropane trimercaptopropionate and 6.33g of 1,6-hexamethylene diisocyanate, add 0.02g of dibutyltin diacetate as a catalyst, and mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0048] Embodiment 2:

[0049] Weigh 10g of trimethylolpropane trimercaptopropionate and 8.37g of isophorone diisocyanate, add 0.02g of catalyst triethylamine, mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0050] Embodiment 3:

[0051] Weigh 10g of trimethylolpropane trimercaptopropionate and 6.55g of toluene-2,4-diisocyanate, add 0.03g of a catalyst imidazole compound, and mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0052] Embodiment 4:

[0053] Weigh 10g of pentaerythritol tetramercaptopropionate and 6.88g of 1,6-hexamethylene diisocyanate, add 0.03g of dibutyltin diacetate as a catalyst, and mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0054] Embodiment 5:

[0055] Weigh 10g of pentaerythritol tetramercaptopropionate and 9.09g of isophorone diisocyanate, add 0.06g of catalyst triethylamine, mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0056] Embodiment 6:

[0057] Weigh 10g of pentaerythritol tetramercaptopropionate and 7.12g of toluene-2,4-diisocyanate, add 0.05g of a catalyst imidazole compound, mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0058] Embodiment 7:

[0059] Weigh 10g of triphenylene-2,3,6,7,10,11-hexamethylene mercaptan and 11.99g of 1,6-hexamethylene diisocyanate, add 0.09g of dibutyltin diacetate as a catalyst, and mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0060] Embodiment 8:

[0061] Weigh 10g of triphenylene-2,3,6,7,10,11-hexamercaptan and 15.85g of isophorone diisocyanate, add 0.10g of catalyst triethylamine, mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0062] Embodiment 9:

[0063] Weigh 10g of triphenylene-2,3,6,7,10,11-hexamercaptan and 12.42g of toluene-2,4-diisocyanate, add 0.11g of a catalyst imidazole compound, mix well to obtain a plugging agent. Inject the plugging agent into the leaking condenser heat exchange tube and allow it to solidify naturally, so as to achieve rapid plugging of the condenser heat exchange tube.

[0064] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A condenser rapid plugging method based on mercapto-isocyanate click reaction, characterized in that: The method comprises: The compound containing a mercapto group and the compound containing an isocyanate group are mixed at room temperature in a molar ratio of the mercapto group to the isocyanate group of 1:1 to obtain a leak-proof agent; Mix the plugging agent and the catalyst evenly; The plugging agent mixed with the catalyst is filled into the leaking condenser heat exchange tube, and the plugging agent is waited for to solidify by itself, so that the quick plugging of the condenser heat exchange tube can be completed.

2. The method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction according to claim 1, characterized in that: The compound containing thiol group is a multifunctional thiol compound.

3. The method for rapid leak plugging of a condenser based on mercapto-isocyanate click reaction according to claim 2, characterized in that: The mercapto group-containing compound includes trimethylolpropane trimercaptopropionate, pentaerythritol tetramercaptopropionate, or triphenylene-2,3,6,7,10,11-hexathiol.

4. The method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction according to claim 1, characterized in that: The isocyanate-containing compound is a multifunctional isocyanate compound.

5. The method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction according to claim 4, characterized in that: The isocyanate-containing compound includes hexamethylene diisocyanate, isophorone diisocyanate, or toluene-2,4-diisocyanate.

6. The method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction according to claim 1, characterized in that: The catalyst is a catalyst for mercapto-isocyanate reaction.

7. A condenser rapid plugging method based on mercapto-isocyanate click reaction according to claim 6, characterized in that: The catalyst includes dibutyltin diacetate, triethylamine, or an imidazole compound.

8. The method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction according to claim 1, characterized in that: The mass ratio of the plugging agent to the catalyst should be 0.1% to 0.5%.

9. The method for rapid leak plugging of a condenser based on mercapto-isocyanate click reaction according to claim 1, characterized in that: The method of filling the plugging agent mixed with the catalyst into the leaking condenser heat exchange tube and waiting for the plugging agent to solidify by itself can complete the rapid plugging of the condenser heat exchange tube, including: The plugging agent mixed with the catalyst is filled into the leaking condenser heat exchange tube. Under the joint catalysis of the catalyst and the moisture in the heat exchange tube, a mercapto-isocyanate click reaction occurs, which solidifies to form a polymer resin material, thereby achieving rapid plugging of the condenser.

10. The method for rapid plugging of condenser leaks based on mercapto-isocyanate click reaction according to claim 1, characterized in that: The solidification and plugging time is controlled within 5 to 30 minutes, and with the contact with water, the plugging agent will be further deeply solidified and form hydrogen bonds with the heat exchange tube wall, thereby strengthening the bonding strength with the tube wall to enhance the plugging effect.

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