CN107987901B

CN107987901B - Method for preparing nano fluid fuel on line

Info

Publication number: CN107987901B
Application number: CN201711156292.8A
Authority: CN
Inventors: 刘冬; 刘冠楠
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2017-11-20
Filing date: 2017-11-20
Publication date: 2020-04-07
Anticipated expiration: 2037-11-20
Also published as: CN107987901A

Abstract

The invention discloses a method for preparing nano fluid fuel on line, which can effectively reduce the emission of carbon smoke particles and nitric oxide of a combustion device and realize supply and demand balance through the method for preparing nano fluid fuel on line and a device for preparing nano fluid fuel on line, namely the volume of the fuel used by the combustion device is equal to the volume of fuel mixed by ultrasonic, thereby effectively reducing the occurrence of the sedimentation phenomenon of nano particles and reducing unnecessary energy consumption loss.

Description

Method for preparing nano fluid fuel on line

Technical Field

The invention belongs to the field of fuel preparation and supply, and particularly relates to a method for preparing a nanofluid fuel on line.

Background

With the increase of the quality of life and the consumption level of people, the automobile industry develops at a high speed and becomes one of the post industries in China. The environmental pollution problem caused by the increase of the automobile usage amount is also becoming more serious. Compared with gasoline engine, diesel engine has the advantages of good fuel economy and pollutants (CO, CO)₂And HC) emissions are relatively small, and most urban buses and industrial equipment are powered by diesel engines. However, there is a serious problem in the application of the diesel engine, that is, Particulate Matter (PM) and Nitrogen Oxide (NO)_x) The amount of emissions is high. The size of PM is only micron and submicron grade, and respiratory diseases and other diseases which are harmful to human bodies can be caused when PM is inhaled into the lung; atmospheric nitrogen oxides can cause damage to the central nervous system of the human body, causing spasticity and paralysis. Therefore, the control of pollutant emissions is imminent and becomes a key and difficult point in diesel engine technology, which greatly limits the development of modern diesel engines.

The nano fluid fuel is prepared by dispersing metal or nonmetal nano particles into a fuel base liquid to prepare a uniform, stable and high-heat-conductivity suspension. The nano particles can release a large amount of heat along with the combustion of the fuel base liquid, reduce the pressure peak value of an engine, improve the braking heat efficiency and the braking fuel consumption rate, and reduce the emission of nitrogen oxides and soot.

Meanwhile, the application of nanofluid fuel is greatly limited, mainly because the suspension is difficult to maintain stability, and particles are difficult to trap after combustion. At present, common methods for stabilizing the suspension include reducing the particle size of the nanoparticles, adding a dispersant, adjusting the pH value, performing ultrasonic vibration and the like, but only nanofluid fuel with low concentration of the nanoparticles can be obtained, and for the nanofluid fuel with high concentration, the nanoparticles can still rapidly aggregate and sink.

The nano-level metal particles have larger specific surface area and are easy to ignite and burn. The metal aluminum particles with the particle size of 100nm can be ignited under the environment of about 250 ℃, and the ignition temperature is far lower than that of the metal aluminum. The nano particles are added into the traditional hydrocarbon fuel, can be oxidized along with the combustion of the hydrocarbon fuel, release a large amount of energy, have energy density far higher than that of gasoline and diesel oil, and can be used as a potential energy carrier; meanwhile, the hydrocarbon fuel is combusted more fully, the combustion efficiency of the fuel can be improved, and the emission of pollutants is reduced.

Selvan et al investigated the combustion characteristics of a cerium oxide-diesel blend fuel with a single cylinder compression ignition engine, and significantly reduced emissions of carbon monoxide and nitrogen oxides were obtained after adding 25ppm of cerium oxide to the diesel fuel. Kao et al studied the combustion characteristics of diesel fuel with nano-aluminum particles, and found that the combustion heat of the fuel was considerably increased, the fuel consumption was reduced, and the emission of smoke and nitrogen oxides was significantly reduced after the nano-particles were added. Research by Mehta et AL shows that the nano-fluid fuel added with AL, B and Fe can reduce the peak value of the cylinder pressure under full load operation by 59 percent, 60 percent and 62 percent respectively; under the condition of generating the same braking power, the fuel added with a small amount of nano aluminum particles can reduce the fuel consumption by 7 percent; the temperature of the gas discharged by combustion of the nano fluid fuel added with AL, B and Fe is respectively increased by 9%, 7% and 4%, and the effective thermal efficiency is respectively increased by 9%, 4% and 2%.

At present, a plurality of technologies can reduce the oxidation temperature of the soot particles by coating the catalyst on the pipeline, and the soot particles are contacted with the catalyst in a loose mode, so the catalysis does not achieve the ideal effect. In the system, the nanoparticles are embedded into the generated soot particles in a close contact manner, so that the oxide temperature of the soot particles can be greatly reduced, and the aim of passive regeneration is fulfilled. Some researchers have systematically demonstrated that a smaller amount of catalyst not only has a catalytic effect on the maturation of a mature soot but also has a significant effect on the degree of graphitization of the soot during its formation, based on olefin, alkane gas fuels with added catalyst.

Hu et al added 0.1-0.2 volume fraction of ferrocene to propane fuel, found that the crystallite size of the soot generated at the end of the flame was shortened and the interlayer spacing and curvature of the crystallites were both increased. The change of the microstructure of the Soot proves that the ferrocene hinders the graphitization of the Soot in the Soot generation and improves the oxidation activity. Kim et al investigated the effect of adding 0.1 mol% iron pentacarbonyl on the oxidative activity of ethylene fuel to produce a root, and found that the activation energy of the root decreased from around 162KJ/mol to around 116 KJ/mol. Rinkenharger et al added different alkali metal salts to propane fuel, explored the influence of alkali metal salts on the oxidation activity of the fuel during the formation of the soot and after maturation, and found that the addition of a small amount of K2CO3 has the strongest catalytic effect, and the temperature corresponding to the highest catalytic activity rate of the soot can be reduced to 300 ℃.

Disclosure of Invention

Based on the combustion characteristics of the nano fluid fuel, the invention provides a method for preparing the nano fluid fuel on line aiming at two problems in the application of the nano fluid, which can effectively reduce the emission of soot particles and nitric oxide of a combustion device such as an engine, can realize supply and demand balance, namely the volume of the fuel used by the combustion device is equal to the volume of the fuel mixed by ultrasonic, effectively reduces the occurrence of the sedimentation phenomenon of nano particles, reduces unnecessary energy consumption loss, and has the characteristics of less energy consumption, high efficiency and low cost.

The technical solution for realizing the purpose of the invention is as follows: an on-line preparation method of nano fluid fuel, which comprises the steps of arranging a device for preparing nano fluid fuel between a fuel tank and a combustion device, determining the required amount of liquid fuel according to the working condition requirement of the combustion device, supplying the required liquid fuel through the fuel tank, and mixing the liquid fuel with a corresponding amount of nano particles by the device for preparing nano fluid fuel before supplying the liquid fuel to the fuel tank, wherein the nano particles are metal particles.

The invention has the following beneficial effects: (1) the mode of preparing the nano fluid fuel on line is adopted, the nano fluid fuel is injected into the combustion device in real time, and the sedimentation phenomenon of nano particles in the combustion process is effectively relieved.

(2) Not only reduce NO_xAnd carbonThe discharge of pollutants such as smoke particles and the like can improve the utilization rate of fuel.

(3) The whole system has less energy consumption, simple structure and strong practicability.

(4) The engine can be applied to various engine systems, such as automobile engines, can be practically applied to various combustion chambers in factories and the like, and has strong popularization.

(5) Only the device for preparing the nano fluid fuel on line is connected to the front end of the combustion device, so that the cost is low.

(6) The energy consumption part of the system is mainly an ultrasonic generator which only acts on the local part, so that the energy consumption is low, and the energy waste can be reduced by depending on the energy generated by the automobile in the motion process.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail with reference to the following drawings

Drawings

Fig. 1 is a schematic view of the overall structure of the apparatus for on-line preparation of nanofluid fuel according to the present invention.

Fig. 2 is a schematic view of the internal structure of the apparatus for on-line preparation of nanofluid fuel according to the present invention.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

Referring to fig. 1, a method for preparing nanofluid fuel on-line includes disposing a device for preparing nanofluid fuel between a fuel tank and a combustion device, determining a required amount of liquid fuel according to operating requirements of the combustion device, supplying the required liquid fuel through the fuel tank, and mixing the liquid fuel with a corresponding amount of nanoparticles, which are metal particles, through the device for preparing nanofluid fuel before supplying the liquid fuel to the combustion device.

An apparatus for preparing nano fluid fuel on line comprises a powder feeding device 1, a liquid fuel supply pipe 2, a mixer 4, a liquid fuel output pipe 5, an ultrasonic oscillator 9 and a liquid fuel supply control device 10, wherein the mixer 4 is positioned at the lower end of the powder feeding device 1, the mixer 4 is communicated with the liquid fuel supply pipe 2 and the powder feeding device 1, the ultrasonic oscillator 9 is arranged at the side surface of the mixer 4, the liquid fuel supply control device 10 is arranged at the lower end of the mixer 4 and is used for controlling the supply of nano fluid fuel, and the liquid fuel output pipe is used for supplying nano fluid fuel to a combustion device, wherein nano particles are metal particles.

Further, with reference to fig. 2, the powder feeding device 1 includes an upper cover 6 located at the upper end thereof and a powder containing tray 8 located at the lower end thereof, a powder storage chamber 7 is formed inside the powder feeding device 1 to contain nanoparticles, a powder feeding hole communicating the powder storage chamber 7 with the mixer 4 is formed in the powder containing tray 8, a powder feeder is arranged inside the powder feeding device 1, and the powder feeder is controlled by a control steering engine 3 located at the lower end of the powder containing tray 8 to realize and adjust the supply of the nanoparticles.

Furthermore, the powder feeder comprises a central shaft, the bottom end of the central shaft is connected with the control steering engine, the top end of the central shaft penetrates through the upper cover 6, the part of the central shaft, which is located inside the powder storage cavity 7, is connected with a cross rod, the central shaft penetrates through the middle part of the cross rod, two ends of the cross rod are respectively connected with a pushing and sweeping block, and the central shaft can drive the cross rod to rotate so as to drive the pushing and sweeping block to push the nanoparticles into the powder feeding hole.

Further, the liquid fuel supply pipe 2 is connected to a fuel tank.

Further, the liquid fuel supply pipe 2, the mixer 4, and the ultrasonic oscillator 9 are all plural and equal in number.

Further, the nanoparticles are metallic or non-metallic particles.

Further, it is characterized in that: the fuel is diesel oil.

Further, it is characterized in that: the combustion device is an engine.

Further, the steering engine is a KST215 steering engine.

The specific working process and mechanism are as follows: the nano particles are used as additives to be mixed with the liquid fuel to form uniform and stable nano fluid fuel, so that the emission of pollutants can be reduced, and the energy density of the base liquid fuel can be obviously increased. Since the density of the nano particles is higher than that of the liquid fuel, even if the surfactant is added, only uniform nano fluid with low concentration can be prepared, and the nano fluid is difficult to suspend in the base fluid for a long time. The occurrence of the phenomenon of nano particle sedimentation not only can influence the combustion of nano fluid, but also can block the pipeline more easily. The system adopts a mode of on-line preparation, namely mixing and using the nano fluid fuel, and a device for on-line preparation of the nano fluid fuel is additionally arranged between a fuel tank and a combustion device, as shown in figure 1. Taking fuel oil as an example of fuel, sweeping quantitative nano particles into a powder containing disc through a powder feeder; then the fuel oil is flushed through the oil inlet and enters the mixer; then the mixed fuel oil is prepared in a certain proportion through the oscillation of the ultrasonic generator, and the liquid fuel supply control device rotates to open the pipeline, so that the oil supply is realized. The whole system is divided into two branches, each branch works in parallel, and fuel oil and nano particles are controlled to be mixed continuously through a steering engine and are supplied continuously. The system abandons the scheme of continuous ultrasonic vibration of the fuel tank, because the energy consumption is larger when the ultrasonic generator is used for acting on the fuel tank with larger volume for a long time. After the device for preparing the nano fluid fuel on line is added, the supply and demand balance can be realized, namely, the volume of the fuel used by the combustion device is equal to that of the fuel mixed by ultrasonic, and unnecessary energy consumption loss is reduced.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing nano fluid fuel on line is characterized in that a device for preparing nano fluid fuel is arranged between a fuel tank and a combustion device, a required liquid fuel amount is determined according to the working condition requirement of the combustion device, the required liquid fuel is supplied through the fuel tank, and the liquid fuel is mixed with a corresponding amount of nano particles by the device for preparing nano fluid fuel before the liquid fuel is supplied to the combustion device, wherein the nano particles are metal particles.