CN110016635B

CN110016635B - Mixed coating material for gas engine and gas engine using same

Info

Publication number: CN110016635B
Application number: CN201910372443.6A
Authority: CN
Inventors: 杨君; 孙波; 王金波; 李延骁; 张克松; 高岩飞; 刘永辉
Original assignee: Shandong Jiaotong University
Current assignee: Shandong Jiaotong University
Priority date: 2019-05-06
Filing date: 2019-05-06
Publication date: 2020-05-15
Anticipated expiration: 2039-05-06
Also published as: CN110016635A

Abstract

A mixed coating material for a gas engine and the gas engine using the material are prepared from the following raw materials in parts by mass: molybdenum disulfide: 10-15 parts; nickel oxide: 50-80 parts; transition metal oxide: 2-10 parts; boron nitride or silicon carbide: 1-3 parts. Boron nitride or silicon carbide is added, and firstly, the boron nitride or the silicon carbide is used as an additive, so that various substances can be promoted to be ground and reduced; and secondly, providing a defect position, thereby promoting the separation of the carbon deposit, avoiding the generation of the carbon deposit and prolonging the service time.

Description

Mixed coating material for gas engine and gas engine using same

Technical Field

The application relates to a mixed coating material for a gas engine and the gas engine using the same.

Background

The engine is the heart of the vehicle, and the performance of the engine directly influences the performance of the vehicle. In recent years, gas automobiles, namely automobiles using natural gas, liquefied petroleum gas and the like as fuels are popularized in China, and the main purpose of the popularization of the fuel is to reduce the discharge amount of pollutants, so that the carbon deposition phenomenon is weaker than that of automobiles burning gasoline and diesel oil, but the popularization has own characteristics. Because the carbon deposition process of the fuel gas is a slow deposition process, the deposition is slow, so that the position where the carbon deposition can be contacted with the engine can gradually form very stable carbon deposition, and the condition can become very serious as the time is prolonged and the adhesion is good if the carbon deposition is not processed in time.

Disclosure of Invention

In order to solve the problems, the application provides a mixed coating material for a gas engine and the gas engine using the same, and on one hand, the mixed coating material for the gas engine comprises the following substances in parts by mass: molybdenum disulfide: 10-15 parts; nickel oxide: 50-80 parts; transition metal oxide: 2-10 parts; boron nitride or silicon carbide: 1-3 parts. Boron nitride or silicon carbide has two functions: firstly, boron nitride or silicon carbide is used as an additive, and has a certain effect of accelerating ball milling treatment, so that various substances are mixed more uniformly; the second is that the better the flatness of the coating is, the more carbon deposition resistant the coating is, but for a gas engine, the more slow the carbon deposition accumulation is, the better stability after the formation is slowly caused, so that the high flatness is not very large in effect, but after boron nitride or silicon carbide is introduced, the boron nitride or silicon carbide is used as a center to cause a 'defect position', which is generally a convex position, and the separation phenomenon can occur when the gas engine is started after the carbon deposition is slowly caused on the surface of the coating in the use process. Therefore, the coating improves the carbon deposition resistance of the coating by peeling off the coating from the carbon deposition, but not improves the surface flatness of the coating to improve the carbon deposition resistance of the coating.

Preferably, the coating material is synthesized according to the following method: the transition metal oxide is a lanthanide metal oxide; the mesh number of the boron nitride or the silicon carbide is 4000-6000 meshes.

Preferably, the coating material is synthesized according to the following method: molybdenum sulfide, nickel oxide, transition metal oxide, boron nitride or silicon carbide are forcibly mixed, and then granulation and crushing treatment are sequentially carried out. By the method, the whole mixing effect can be improved, so that various substances can be ubiquitous in a narrow space.

Preferably, the forced mixing is performed as follows: the preparation raw materials are sequentially put into a ball mill and then ball-milled. The ball milling treatment enables the boron nitride and the silicon carbide to play a role of grinding materials, so that the mesh size of the whole system is better improved, and the problem of better improving the mixing uniformity in the whole system is solved.

Preferably, the preparation raw materials after forced mixing are added with a binder, a dispersant and water to obtain slurry, then the slurry is used for preparing raw materials into agglomerates to obtain primary particles, and then the primary particles are dried and ball-milled.

Preferably, the slurry is spray dried to obtain dry granules. Avoiding the occurrence of integral agglomeration phenomenon and keeping the independence among the particles in the particle as much as possible.

On the other hand, the inner surface of the gas engine is sprayed with a protective coating obtained by mixing coating materials. The coating with the protruding defect positions can be obtained by utilizing the coating material, so that when carbon deposition is attached, the carbon deposition can be attached to the protruding defect positions insecurely, even if the carbon deposition of a gas engine is slow, uniform attachment still cannot be completed, and therefore in the starting stage, the coating can take the defect positions as starting points due to sudden heat, and part of the carbon deposition can be stripped from the coating; in addition, the raw materials are uniformly mixed, so that carbon deposition points are more, and the problem of carbon deposition is reduced.

Preferably, the hybrid coating is applied to the inner surface of the gas engine by a plasma spray process to obtain a protective coating.

Preferably, the protective coating has a thickness of 0.3 to 0.5 mm.

Preferably, the plasma spraying method operates at a core temperature of not higher than 1350 ℃. The spraying is carried out at a relatively controlled temperature, mainly because the high-temperature working condition has an influence on the preservation of the internal substances and the catalytic activity of the coating material.

This application can bring following beneficial effect:

1. boron nitride or silicon carbide is added, and firstly, the boron nitride or the silicon carbide is used as an additive, so that various substances can be promoted to be ground and reduced; secondly, providing defect sites to promote the detachment of the carbon deposit;

2. the whole mixing effect can be improved by the way of forced mixing, and then granulation and crushing are carried out in sequence, so that various substances can universally exist in a narrow space;

3. the spray drying mode is adopted, so that the integral agglomeration phenomenon is avoided, and the independence among all particles in the particle is kept as much as possible;

4. the application carries out the spraying under a relatively controllable temperature, mainly because the high temperature operating mode causes the influence to the save of inside material and the catalytic activity of coating material itself.

Detailed Description

In order to clearly illustrate the technical features of the present solution, the present application will be explained in detail through the following embodiments.

For the synthesis of the coating material, the following steps are firstly carried out:

s1, firstly, taking the raw materials as shown in the table 1;

s2, adding the raw materials in the S1 into a ball mill, and carrying out ball milling for 1.5 h;

s3, taking the powder obtained in the step S2, adding a binder, a dispersing agent and a proper amount of water to obtain slurry according to the amount shown in the table 1, wherein the amount of the added water is not less than 2 times of the total mass;

and S4, carrying out spray drying on the slurry obtained in the step S3 to obtain dried particles, carrying out ball milling on the dried particles to obtain a spraying material, wherein the particle size of the spraying material is not more than 1000 meshes.

Table 1:

for the properties of the substances, the substances are used for the coating design of the gas engine in the following way, the spraying materials are sprayed on the surface of a metal plate which is the same as the engine by using a plasma spraying method, then the metal plate is directly sprayed on the surface of the metal plate by using a gas spray gun, the gas spray gun is in an insufficient combustion state, the test conditions are shown in table 2, and the area ratio of carbon deposition which is obviously visible to naked eyes is measured on the surface of the metal plate.

For the test with the serial number 7, molybdenum disulfide does not exist, for the test with the serial number 8, nickel oxide does not exist, for the test with the serial number 9, transition metal oxide does not exist, and the carbon deposition area of any substance reduced on the surfaces of the three tests can be increased; in the test No. 10, the area ratio was very high without boron nitride or silicon carbide, and it is estimated that the removal of carbon deposition was promoted when boron nitride or silicon carbide was present; for the test with serial number 11, the particle size of boron nitride or silicon carbide is too high, and it is presumed that under such a condition, when the particle size of boron nitride or silicon carbide is too large, the surface defect sites are too large, so that the boron nitride or silicon carbide cannot be uniformly distributed in the ball milling process, thereby affecting the performance of the coating and having a large carbon deposition area.

Table 2:

serial number	Thickness of protective coating (mm)	Center temperature (. degree. C.)	Time (h)	Area ratio (%)
					1	0.3	1350	5	25
2	0.4	1300	5	26
					3	0.5	1350	5	28
4	0.3	1300	5	31
					5	0.4	1350	5	30
6	0.5	1300	5	29
					7	0.4	1300	5	48
8	0.4	1300	5	46
					9	0.4	1300	5	41
10	0.4	1300	5	81
					11	0.4	1300	5	65

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A mixed coating material for a gas engine, characterized in that: the preparation raw materials comprise the following substances in parts by mass: molybdenum disulfide: 10-15 parts; nickel oxide: 50-80 parts; transition metal oxide: 2-10 parts; boron nitride or silicon carbide: 1-3 parts; the transition metal oxide is a lanthanide metal oxide.

2. The hybrid coating material for a gas engine according to claim 1, characterized in that: the mesh number of the boron nitride or the silicon carbide is 4000-6000 meshes.

3. The hybrid coating material for a gas engine according to claim 1, characterized in that: the coating material is synthesized according to the following method: molybdenum sulfide, nickel oxide, transition metal oxide, boron nitride or silicon carbide are forcibly mixed, and then granulation and crushing treatment are sequentially carried out.

4. The hybrid coating material for a gas engine according to claim 3, characterized in that: the forced mixing is carried out in the following way: the preparation raw materials are sequentially put into a ball mill and then ball-milled.

5. The hybrid coating material for a gas engine according to claim 3, characterized in that: the granulation is carried out in the following manner: and adding a binder, a dispersing agent and water into the forcibly mixed preparation raw materials to obtain slurry, then preparing the raw materials into agglomerates by using the slurry to obtain primary particles, and then drying the primary particles and carrying out ball milling.

6. The hybrid coating material for a gas engine according to claim 5, characterized in that: the slurry is subjected to spray drying to obtain dried granules.

7. A gas engine using the hybrid coating material of any one of claims 1 to 6, characterized in that: the inner surface of the gas engine is sprayed with a protective coating obtained by mixing coating materials.

8. A gas engine using a hybrid coating material according to claim 7, wherein: the mixed coating is applied to the inner surface of the gas engine by a plasma spraying method to obtain a protective coating.

9. A gas engine using a hybrid coating material as in claim 8, wherein: the thickness of the protective coating is 0.3-0.5 mm.

10. A gas engine using a hybrid coating material as in claim 8, wherein: the plasma spraying method operates at a core temperature of not higher than 1350 ℃.