Anti-coking high-temperature gas turbine lubricating oil composition with extreme pressure property and preparation method thereof

Abstract

The invention provides an anti-coking high-temperature gas turbine lubricating oil composition with extreme pressure property and a preparation method thereof, and relates to the technical field of lubricating oil. The anti-coking high-temperature gas turbine lubricating oil composition with the extreme pressure property is prepared from the following components in percentage by mass: 0.3 to 0.6 percent of a phenolic ester antioxidant, 0.3 to 0.5 percent of other antioxidants, 0.05 to 0.10 percent of a metal deactivator, 0.01 to 0.02 percent of a demulsifier, 0.01 to 0.02 percent of an anti-foaming agent, 0.03 to 0.04 percent of an anti-wear reagent at extreme pressure, 0.05 to 0.10 percent of an anti-rust agent and the balance of base oil, the phenolic ester antioxidant has the following structural general formula: x is selected from an integer of 1-5, and n is selected from an integer of 12-20. The high-temperature gas turbine lubricating oil composition provided by the invention shows excellent anti-coking, anti-oxidation and anti-rust properties.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, and more specifically, to an extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition and its preparation method. Background Technology

[0002] A gas turbine is an internal combustion engine that uses a continuously flowing gas as its working fluid to drive a high-speed rotating impeller, converting the energy of fuel into useful work. It is a type of rotating impeller-type thermal engine. With continuous advancements in high-temperature materials and the adoption of cooling blades in turbines to improve cooling efficiency, the initial gas temperature has gradually increased, leading to continuous improvements in gas turbine efficiency and single-unit power. Due to its extremely high technological content, conventional steam turbine lubricating oils are insufficient for prolonged operation under harsh conditions. Major original equipment manufacturers (OEMs) worldwide have imposed higher requirements on gas turbine lubricating oils to ensure equipment safety and normal operation.

[0003] Patent CN102618367B invented a lubricating oil composition for biogas power generation gas turbines, using a high-alkalinity detergent and PAO base oil, and the oil meets the operating requirements. However, the metal elements contained in the metal detergent itself can easily cause additional coking problems during the operation of the gas turbine and affect the demulsibility of the gas turbine lubricating oil.

[0004] Patent CN105733762A discloses a low-sludge turbine lubricating oil composition, which can well meet the lubrication requirements of steam turbines and gas turbines with low sludge requirements. However, the product does not possess extreme pressure properties. Compared to ordinary products, extreme pressure products have stronger polarity, making them more likely to combine with metals and produce coking.

[0005] Patent CN113493719A discloses a gas turbine oil that uses ionic liquid as the core component of the lubricant additive, which inhibits the formation of sludge in the lubricant and improves its demulsibility and rust prevention properties, but does not involve the improvement of the anti-coking performance of high-temperature gas turbines.

[0006] Patent CN1109478A discloses an improved method for applying a composite alkylphenol ester antioxidant. Using this composite antioxidant can increase the oxidation induction period of oil products by several times and improve the antioxidant performance of oil products. However, although the formation of varnish film on oil products is closely related to the base oil and the antioxidant, the oxidation induction period and the ease of varnish film formation do not show a positive correlation. This composite alkylphenol ester antioxidant does not solve the problem of easy coking during use.

[0007] Patent CN108641787A discloses an environmentally friendly high-temperature resistant lubricating oil, comprising high molecular weight phenolic ester antioxidants, dispersants, and sulfurized alkylphenol calcium, etc. The environmentally friendly high-temperature resistant lubricating oil provided by this invention is low in phosphorus, environmentally friendly, and resistant to high temperatures and high loads, effectively reducing carbon emissions and environmental pollution. However, the phenolic ester antioxidant in this formulation does not contain phosphorus, and the formulation contains metal detergents and a large amount of Mannich base dispersants, making it unsuitable for gas turbine compressor oils that are prone to water ingress, adversely affecting the oil's water separation performance.

[0008] Therefore, there is an urgent need to provide a high-temperature gas turbine lubricating oil composition with stable and excellent performance that meets the requirements of anti-coking properties under harsh operating conditions of high temperature, high speed and extreme pressure. Summary of the Invention

[0009] To address the problems existing in the prior art, this invention uses a specific phenolic ester antioxidant to form a compound system with other antioxidants. At the same time, by screening metal passivators, antifoaming agents, demulsifiers, antioxidants, extreme pressure agents, etc., it provides a high-temperature gas turbine lubricating oil composition with extreme pressure properties that is stable and excellent in performance and meets the harsh operating conditions of high temperature, high speed and extreme pressure in gas turbines.

[0010] The first aspect of the present invention is to provide an extreme pressure anti-coking high-temperature gas turbine lubricating oil composition, comprising, by weight percentage: 0.3-0.6% phenolic ester antioxidant, 0.3-0.5% other antioxidants, 0.05-0.10% metal passivator, 0.01-0.02% demulsifier, 0.01-0.02% antifoaming agent, 0.03-0.04% extreme pressure anti-wear agent, 0.05-0.10% rust inhibitor, with the balance being base oil;

[0011] The phenolic ester antioxidant has the following general structural formula:

[0012]

[0013] Where X is selected from integers 1 to 5, and n is selected from integers 12 to 20.

[0014] Preferably, X is selected from an integer from 1 to 3, and n is selected from an integer from 12 to 16.

[0015] Preferably, the synthesis process of the phenolic ester antioxidant is as follows:

[0016] Step 1: Intermediate A is synthesized by reacting alkylphenol and 37% formaldehyde solution at 50°C under nitrogen protection.

[0017]

[0018] Step 2: Intermediate B is synthesized by reacting intermediate A and polyene polyamine at 50°C under nitrogen protection.

[0019]

[0020] Step 3: Using alkylphenols and triethyl phosphite as raw materials and anhydrous potassium carbonate as a catalyst, intermediate C is synthesized via transesterification.

[0021]

[0022] Step 4: Using intermediates B and C as raw materials and anhydrous potassium carbonate as a catalyst, the final product, phenolic ester antioxidant, is synthesized through transesterification.

[0023]

[0024] Preferably, the other antioxidant is selected from at least one of thiocarbamate, 2,6-di-tert-butyl-p-cresol, octylphenyl-α-naphthylamine, dioctyldiphenylamine, dinonyldiphenylamine, octylbutyldiphenylamine, nonylbutyldiphenylamine, styryloctyldiphenylamine, and α-methylstyryldiphenylamine.

[0025] More preferably, the other antioxidant is selected from at least one of 2,6-di-tert-butyl-p-cresol, dioctyl diphenylamine, and octylphenyl-α-naphthylamine.

[0026] Preferably, the metal passivating agent is selected from at least one of alkylthiadiazole, methylbenztriazole, and N,N'-disaline diamine.

[0027] Preferably, the demulsifier is an oil-soluble polyether or a polyoxypropylene derivative.

[0028] Preferably, the antifoaming agent is selected from at least one of composite antifoaming agents, polymethacrylate, and polyacrylate.

[0029] Preferably, the extreme pressure anti-wear agent is selected from at least one of di-n-butyl phosphite, triaryl phosphate, and trialkyl phosphate.

[0030] Preferably, the rust inhibitor is selected from succinic anhydride or organic sulfonate.

[0031] Preferably, the base oil is a polyalphaolefin and a pentaerythritol ester, wherein the mass ratio of the polyalphaolefin to the pentaerythritol ester is 85-90:10.

[0032] A second aspect of the present invention relates to a method for preparing the above-mentioned extreme pressure anti-coking high-temperature gas turbine lubricating oil composition, comprising the following steps:

[0033] After mixing the base oil and the remaining components except the antifoaming agent, stir at 60-65℃ for 1-1.5 hours, then add the antifoaming agent dropwise and stir for 10-20 minutes.

[0034] Preferably, the dripping rate of the antifoaming agent is 10% / min of the total amount of antifoaming agent.

[0035] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses a specific phenolic ester antioxidant and other antioxidants to form a compound system, which exhibits excellent anti-coking, anti-oxidation and anti-rust properties; (2) By screening metal passivators, demulsifiers, defoamers, extreme pressure agents, etc., the additives exhibit good compatibility and synergistic effects, with stable and excellent performance, meeting the harsh working conditions of future ultra-high pressure gas turbines. Attached Figure Description

[0036] Figure 1 Coking tendency diagrams of oils from Examples 1-4 and Comparative Examples 1-2. Detailed Implementation

[0037] Example 1:

[0038]

[0039]

[0040] Example 2:

[0041]

[0042] Example 3:

[0043]

[0044]

[0045] Example 4:

[0046]

[0047]

[0048] Comparative Example 1:

[0049]

[0050] Comparative Example 2:

[0051]

[0052]

[0053] Test Example 1: Coking Tendency of Oil Products

[0054] The oils from Examples 1-4 and Comparative Examples 1-2 were tested according to the MAN Turbomaschinen AG AA-10-217 / AC test method. 100 mL of the test sample was stored in an oven at 180°C for 48 hours. After filtering the sample through a 0.45 μm filter membrane, the color of the filter membrane was observed to determine the oil's coking tendency. The results are shown below. Figure 1 . Figure 1 The results showed that the filter membrane of the oil with added specific phenolic ester antioxidant was significantly lighter in color than that without it, proving that the phenolic ester antioxidant has good anti-coking inhibition ability in extreme pressure oils.

[0055] The performance of the gas turbine oils in Examples 1-4 and Comparative Examples 1-2 was tested, and the test results are shown in Table 1.

[0056] Table 1: Test results of gas turbine oil performance in Examples 1-4 and Comparative Examples 1-2

[0057]

[0058]

[0059] According to the performance test results, in the copper corrosion test, the corrosion of copper sheets by the oils in Examples 1-4 was significantly weaker than that of Comparative Examples 1-2, indicating that the oils in Examples 1-4 had good rust prevention properties. In the rotating oxygen bomb test, the rotating oxygen bomb test time of Examples 1-4 was significantly longer than that of Comparative Examples 1-2. Therefore, the oxidation stability of the oils in Examples 1-4 was better than that of Comparative Examples 1-2. Among the four examples, Example 4 had the shortest rotating oxygen bomb test time of 1758 min, which was more than 20% better than the longest rotating oxygen bomb test time of 1445 min in Comparative Example 2. In the dry TOST test, the amount of sludge in Examples 1-4 was much lower than that in Comparative Examples 1 and 2, indicating excellent anti-coking and anti-oxidation properties.

[0060] This invention employs a compound system obtained by combining a specific phenolic ester antioxidant with other antioxidants, exhibiting excellent anti-coking, antioxidant, and rust-preventive properties. By screening metal passivators, demulsifiers, defoamers, extreme pressure agents, and other additives, the additives demonstrate good compatibility and synergistic effects. The provided anti-coking high-temperature gas turbine lubricating oil composition exhibits stable and excellent performance, meeting the stringent requirements of future ultra-high pressure operating conditions of gas turbines.

[0061] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A high-temperature gas turbine lubricating oil composition with extreme pressure properties and anti-coking properties, comprising the following components by weight percentage: Phenolic ester antioxidant 0.3-0.6%, other antioxidants 0.3-0.5%, metal passivator 0.05-0.10%, demulsifier 0.01-0.02%, antifoaming agent 0.01-0.02%, extreme pressure anti-wear agent 0.03-0.04%, rust inhibitor 0.05-0.10%, balance base oil; The phenolic ester antioxidant has the following general structural formula: Where X is selected from integers 1 to 5, and n is selected from integers 12 to 20.

2. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, X is selected from integers from 1 to 3, and n is selected from integers from 12 to 16.

3. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The other antioxidants are selected from at least one of thiocarbamate, 2,6-di-tert-butyl-p-cresol, octylphenyl-α-naphthylamine, dioctyl diphenylamine, dinonyl diphenylamine, octylbutyl diphenylamine, nonylbutyl diphenylamine, styryloctyl diphenylamine, and α-methylstyryl diphenylamine.

4. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 3, characterized in that, The other antioxidants are selected from at least one of 2,6-di-tert-butyl-p-cresol, dioctyl diphenylamine, and octylphenyl-α-naphthylamine.

5. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The metal passivating agent is selected from at least one of alkylthiadiazole, methylbenztriazole, and N,N'-disaline diamine.

6. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The demulsifier is an oil-soluble polyether or a polyoxypropylene derivative.

7. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The antifoaming agent is selected from at least one of composite antifoaming agents, polymethyl methacrylate, and polyacrylate.

8. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The extreme pressure anti-wear agent is selected from at least one of di-n-butyl phosphite, triaryl phosphate, and trialkyl phosphate.

9. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The rust inhibitor is selected from succinic anhydride or organic sulfonate.

10. The extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to claim 1, characterized in that, The base oil is a polyalphaolefin and a pentaerythritol ester, wherein the mass ratio of the polyalphaolefin to the pentaerythritol ester is 85-90:

10.

11. A method for preparing an extreme pressure, anti-coking, high-temperature gas turbine lubricating oil composition according to any one of claims 1-10, comprising the following steps: After mixing the base oil and the remaining components except the antifoaming agent, stir at 60-65℃ for 1-1.5 hours, then add the antifoaming agent dropwise and stir for 10-20 minutes.

12. The preparation method according to claim 11, characterized in that, The dripping rate of the antifoaming agent is 10% / min of the total amount of antifoaming agent.

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