A technology and implementation method for double drag reduction in fire water supply system

Abstract

The present invention relates to a technology and implementation method for dual drag reduction of fire water supply system, belonging to the technical field of fire equipment. The technology of the present invention realizes dual drag reduction of water supply system by adding surfactant to fire water and coating hydrophobic coating on the inner surface of water hose at the same time. The specific implementation method of the technology is: using molecular simulation to obtain the average water molecule adsorption amount of surfactant, coating and surfactant-coating system respectively, and combining contact angle test experiment to screen drag reduction system. The specific implementation steps of the method are: 1. Based on molecular simulation, construct and optimize surfactant and coating molecules; 2. Simulate water molecule adsorption and screen materials according to the average adsorption amount; 3. Calculate the average water molecule adsorption amount of drag reduction system and complete the screening; 4. Contact angle test experiment verification. In this technology, surfactant reduces the surface tension of solution, coating reduces surface energy and changes surface microstructure, and its implementation method has the characteristics of high efficiency, fastness and low cost.

Description

Technical Field

[0001] The invention relates to a technology and an implementation method for double drag reduction in a fire water supply system, belonging to the technical field of fire equipment. Background Art

[0002] Fire is one of the most frequent disasters in the world. It not only causes material property losses, threatens people's lives and health, but also destroys the ecological balance. With the continuous development of the material society, the risk of fire has expanded, leading to frequent fire accidents. Safe and efficient firefighting has become the focus of reducing fire losses and ensuring social stability. The fire water supply system is an important guarantee for firefighting and rescue work. Firefighting water is mainly drinking water. Insufficient water supply will lead to obstruction of rescue work, serious fire losses, and even threaten the lives of rescuers. The fire hose is an important component of the fire water supply system. The length of each fire hose is generally stipulated to be 20-25 meters. When the water flows through the hose, it is affected by the resistance along the way, causing energy loss and the total amount of fluid decreasing along the process. Therefore, the resistance reduction of the fire water supply system is not only of great significance for the firefighting work that races against time, but also can effectively save water resources and avoid waste of resources.

[0003] Common forms of drag reduction in fire water supply systems include: on the one hand, adding hydrophobic coatings. Water hose coatings are generally coated with PU, acrylate, chlorosulfonated polyethylene and other coatings on the outer surface of the water hose fabric layer. These materials increase the static contact angle of water on the material surface by providing lower surface energy and a certain rough structure, improve the aging resistance, wear resistance and waterproof performance of the water hose, and ensure the smooth transportation of water or other fire extinguishing materials. On the other hand, add hydrophobic surfactants. Surfactants are composed of two parts: a hydrophilic group (head) and a hydrophobic group (tail). When dissolved in water, they can be arranged at the interface in a directional manner to compensate for the unsaturated force field of the interface, thereby reducing the surface tension of the contact interface and achieving a hydrophobic function. Hydrophobic coatings and surfactants have been widely used in the field of fire protection, but the existing hydrophobic coatings and surfactants are complex and less targeted. In addition, the drag reduction effect of fire water supply systems is mostly achieved through a single material, and an effective connection has not been established between the hydrophobic coating and the surfactant to jointly play a drag reduction role. Therefore, convenient and quick screening of hydrophobic materials and construction of a composite system of hydrophobic coating and surfactant for dual drag reduction can effectively improve firefighting efficiency and reduce fire hazards. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies in the above-mentioned prior art and invent a technology and implementation method for double drag reduction in fire water supply systems. The present invention can realize convenient and rapid screening of hydrophobic coatings and hydrophobic surfactant materials in composite systems, solve the problem that water hose resistance affects the flow and lift of fire water supply systems, improve the performance of fire water supply systems, and thus effectively improve fire rescue efficiency.

[0005] In order to solve the above technical problems, the specific implementation method steps of the technology of the present invention are as follows:

[0006] Step 1: Build molecular models. Determine the basic chemical information of various surfactants and coating molecules, and use the Visualizer and Forcite modules to build and optimize existing molecular models based on Materials Studio 8.0 molecular simulation software and relative molecular mass as a unified standard;

[0007] Step 2, adsorption simulation. Construct a matrix model based on the Monte Carlo method, add a corresponding number of water molecules according to the structural parameters of each molecular layer, and use the Sorption module to simulate the adsorption of water molecules to obtain the average water molecule adsorption amount, adsorption energy, adsorption site, adsorption spacing and other parameters of each system;

[0008] Step 3, screening surfactant molecular materials and coating molecular materials. According to the average water molecule adsorption amount, a variety of surfactant molecular materials and coating molecular materials are screened respectively. The smaller the average water molecule adsorption amount, the better the hydrophobic performance. The selected hydrophobic coating material should be non-toxic, harmless, and lightweight, and the surfactant material should be easily soluble in water and flame retardant;

[0009] Step 4, screening the drag reduction system. The preferred surfactants and coating materials in step 3 are compounded in pairs to obtain a variety of drag reduction systems. Based on molecular simulation, the surfactant-coating molecular simulation system is constructed and optimized, the average water molecule adsorption amount of each system is calculated, and the drag reduction system with excellent performance is screened;

[0010] Step 5, contact angle test experimental verification. Using polyurethane material as the substrate, apply a hydrophobic coating of equal thickness according to the preparation process of each coating material, test and compare the static contact angle and sliding angle between different coating surfaces and distilled water, different solutions and polyurethane surfaces, and each drag reduction system, and calculate the percentage reduction of the contact angle θ of different solutions to verify the feasibility of molecular simulation and determine the drag reduction system with the best performance.

[0011] The dual drag reduction technology for the fire water supply system described in the present invention improves the surface tension of the fire water supply and the hydrophobicity of the fire hose body material, thereby achieving dual drag reduction of the fire hose, thereby improving the head, flow rate and other performance of the fire water supply system. This technology provides a theoretical basis for improving the performance of fire equipment, realizes an efficient, fast and low-cost screening drag reduction system, improves the efficiency of fire rescue, and effectively saves water resources, and has practical application value and realistic significance.

[0012] As a technical solution of the present invention, the method for constructing the molecular structure of the surfactant and the coating in step 1 of the implementation method includes: drawing a molecular model in the Visualizer module based on Materials Studio software. Selecting the Smart minimizer method in the Forcite module under the COMPASS molecular force field to optimize the existing molecular model, and performing annealing kinetics calculations on the model under the NVT and NPT ensembles to overcome the molecular structure energy barrier;

[0013] As a technical solution of the present invention, the Monte Carlo method is used in step 2 of the implementation method to construct a matrix model, including: according to the molecular optimization model obtained in step 1, the Amorphous Cell module in the Materials Studio software is selected to add periodic boundary conditions, and the molecular unit cell structure optimization and annealing kinetics calculation are performed under the boundary conditions to obtain a molecular unit cell density close to the actual density, and on this basis, an aggregate containing multiple molecules is established.

[0014] As a technical solution of the present invention, the method for constructing the drag reduction system in step 4 of the implementation method includes: selecting Build Layers in Materials Studio software to merge the coating molecular layer model and the water molecule supercell, and adding surfactant molecules to the water molecule layer. Smart Minimizer optimization and annealing kinetics calculation are performed on the constructed drag reduction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a process flow chart of the present invention.

[0016] Figure 2 The invention relates to a structural schematic diagram of a fire water supply system, which includes 1-a water hose braided layer, 2-a water hose lining, and 3-a water hose hydrophobic coating. DETAILED DESCRIPTION

[0017] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0018] Reference Figure 1, implement the technology and implementation method of the present invention for double drag reduction of fire water supply system; refer to Figure 2 , a structural schematic diagram of a fire water supply system involved in a specific implementation method of the technology of the present invention.

[0019] Step 1, build a molecular model. Determine the basic chemical information of various surfactants and coating molecules, including molecular formula, density, degree of polymerization, relative molecular mass, etc. Draw the molecular model based on the Visualizer module of Materials Studio 8.0 molecular simulation software. Select the smartminimizer method in the Forcite module under the COMPASS molecular force field to optimize the existing molecular model, and perform annealing kinetics calculations on the model under the NVT and NPT ensembles to overcome the molecular structure energy barrier;

[0020] According to the molecular optimization model obtained in step 1, periodic boundary conditions are added, and the molecular unit cell structure optimization and annealing kinetics calculation are performed under the boundary conditions to obtain the molecular unit cell density that best matches the actual situation. Based on the Monte Carlo method, an aggregate containing 5 molecules is established in the Amorphous Cell Construction module in the Materials Studio software.

[0021] Step 2, adsorption simulation. Using the constructed molecular aggregates, a molecular layer model is constructed with a relative molecular mass of 100,000 or 1 million as a unified standard. According to the structural parameters of each molecular layer, a corresponding number of water molecules are added, and water molecule adsorption simulation is performed in the Sorption module to obtain the average water molecule adsorption amount, adsorption energy, adsorption site, adsorption spacing and other parameters of each system;

[0022] Step 3, screening surfactant molecular materials. Three surfactant molecular materials are screened out according to the average water molecule adsorption amount. The smaller the average water molecule adsorption amount, the better the hydrophobicity. The material should be soluble in water and flame retardant. Figure 2 The surfactant delivery pipeline injects the surfactant solution into the fire water tank and mixes it evenly with the solution agitator;

[0023] Step 4, screening coating molecular materials. Three coating molecular materials are screened out according to the average water molecule adsorption amount. The smaller the average water molecule adsorption amount, the better the hydrophobic property. The material should be non-toxic, harmless, and lightweight. It can be prepared by spin coating, spray coating, sol-gel, etc. Figure 2 Surface layer 3 shown;

[0024] Step 5, screening the drag reduction system. The preferred surfactants and coating materials in (3) and (4) are compounded in pairs to obtain a variety of drag reduction systems. Based on molecular simulation, the surfactant-coating molecular simulation system is constructed and optimized, the average water molecule adsorption amount of each system is calculated, and the drag reduction system with excellent performance is screened;

[0025] Step 6, contact angle test experimental verification. With polyurethane material as the substrate, a hydrophobic coating with an absolute thickness of 10 microns is applied. The German Dataphysics contact angle measuring instrument OCA25 is used, and the measurement mode is static contact angle. The hanging drop method is used to test and compare the static contact angle and sliding angle of different coating surfaces and distilled water, different solutions and polyurethane surfaces, and each drag reduction system. The percentage reduction of the contact angle θ of different solutions is calculated to verify the feasibility of molecular simulation, and then determine the drag reduction system with the best performance.

Claims

1. A technology and implementation method for double drag reduction in fire water supply system, It is characterized in that This technology proposes to add surfactants to fire-fighting water and apply a hydrophobic coating on the inner surface of the fire hose to achieve double drag reduction of the fire-fighting water supply system. The specific steps of this method include: Step 1: construct molecular models, determine the chemical information of various surfactants and coating molecules, and build and optimize existing molecular models based on molecular simulation and relative molecular mass as a unified standard; Step 2, adsorption simulation, adding a corresponding number of water molecules according to the surface area of ​​each molecular layer, and performing water molecule adsorption simulation to obtain the average water molecule adsorption amount of each system; Step 3, screening surfactant molecular materials and coating molecular materials, screening surfactant molecular materials and coating molecular materials according to the average water molecule adsorption amount, the smaller the average water molecule adsorption amount, the better the hydrophobic property, the selected hydrophobic coating material should be non-toxic and harmless, light in weight, etc., the surfactant material should be soluble in water, flame retardant, etc.; Step 4, screening the drag reduction system, compounding the surfactants and coating materials screened in step 3 in pairs to obtain a variety of drag reduction systems, constructing and optimizing the surfactant-coating molecular simulation system based on molecular simulation, calculating the average water molecule adsorption amount of each system, and screening the drag reduction system with excellent performance; Step 5, contact angle test experimental verification, using polyurethane material as the substrate, test and compare the static contact angles and sliding angles of different coating surfaces and distilled water, different solutions and polyurethane surfaces, and various drag reduction systems, and calculate the percentage reduction of the contact angle θ of different solutions to verify the feasibility of molecular simulation.

2. A technology and implementation method for double drag reduction in fire water supply system according to claim 1, It is characterized in that The specific implementation method is to use molecular simulation to obtain the average water molecule adsorption amount of surfactant, coating and surfactant-coating system respectively, and verify it through contact angle test experiment to screen the drag reduction system with the best performance.

3. A technology and implementation method for double drag reduction in fire water supply system according to claim 1, It is characterized in that In step 1 of the implementation method, the surfactant and coating molecular models are drawn based on the Visualizer module of the Materials Studio software, the Smart minimizer method in the Forcite module is selected under the COMPASS molecular force field to optimize the existing molecular model, and the annealing kinetics of the model is calculated under the NVT and NPT ensembles to overcome the molecular structure energy barrier.

4. A technology and implementation method for double drag reduction in fire water supply system according to claim 1, It is characterized in that In step 2 of the implementation method, according to the molecular optimization model obtained in step 1, periodic boundary conditions are added, and the molecular unit cell structure optimization and annealing kinetics calculation are performed under the boundary conditions to obtain the molecular unit cell density, based on which an aggregate containing multiple molecules is established.

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