Long-service-life turbine oil for ammonia-resistant turboset and preparation process of long-service-life turbine oil

Abstract

The invention relates to long-life turbine oil for an ammonia-resistant turboset and a preparation process of the long-life turbine oil. The complexing agent comprises an antioxidant, an anti-rust agent, an anti-wear reagent at extreme pressure, a metal deactivator, a demulsifier, an alkali-resistant stabilizer and base oil, the antioxidant comprises at least two of dinonyl diphenylamine, beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) isooctyl propionate and dialkyl dithiocarbamate, the demulsifier comprises at least two of dialkyl dithiocarbamate, and the alkali-resistant stabilizer comprises at least two of dialkyl dithiocarbamate. The anti-wear reagent at extreme pressure comprises at least two of tricresyl phosphate, thiophosphate and amine salt derivatives thereof, and phosphate and amine salt derivatives thereof, and the alkali-resistant stabilizer comprises polycarboxylic polyether and aliphatic amines. The preparation method comprises the following steps: sequentially adding the components, heating, stirring, mixing at constant temperature, cooling and filtering.

Description

Technical Field

[0001] The present invention relates to a long-life turbine oil for an ammonia-resistant steam turbine unit and a preparation process thereof. Background Art

[0002] With the development of the energy industry and large-scale thermal equipment, steam turbines, as core power equipment in key industries such as electricity, chemical industry, and metallurgy, are highly valued for their operational stability and economic efficiency. As the key working medium for lubrication, cooling, corrosion protection, and sealing of rotating components, turbine oil's performance directly impacts the efficiency and lifespan of the entire unit.

[0003] Currently, turbine oils widely used in the market often utilize multi-component additive systems to enhance their antioxidant, anti-wear, anti-rust, and anti-foam properties. However, traditional formulations often focus on optimizing a single performance indicator. This is particularly true when operating under high loads and in alkaline conditions (such as boiler water treatment residues, condensate backflow, and seawater corrosion). Existing turbine oils commonly suffer from the following issues: Firstly, they lack extreme pressure and anti-wear properties, leading to premature wear of friction pairs; secondly, they are susceptible to saponification, hydrolysis, or precipitation reactions in alkaline environments, resulting in oil degradation, emulsification, and even lubrication failure.

[0004] While some existing composite agents improve individual properties by optimizing antioxidant or anti-wear formulations, they struggle to achieve both anti-wear and alkali stability, resulting in poor adaptability in high-alkaline, water-steam environments. This is particularly true in large steam turbine systems with long continuous operating cycles, where frequent oil changes, oil deterioration, and equipment failures severely impact operating costs and reliability.

[0005] Therefore, how to design a turbine oil compound that has excellent extreme pressure and anti-wear properties and can be used stably for a long time in an alkaline environment has become a technical problem that urgently needs to be solved in this technical field. Summary of the Invention

[0006] The purpose of the present invention is to solve the above deficiencies in the prior art and to provide a long-life turbine oil for an ammonia-resistant steam turbine unit and a preparation process thereof.

[0007] A long-life turbine oil for an ammonia-resistant steam turbine unit, comprising the following components: an antioxidant, a rust inhibitor, an extreme pressure anti-wear agent, a metal deactivator, a demulsifier, an alkali-resistant stabilizer, and a base oil;

[0008] Wherein, the antioxidant comprises at least two of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and dialkyldithiocarbamate;

[0009] The extreme pressure anti-wear agent comprises at least two of tricresyl phosphate, thiophosphate and its amine salt derivatives, and phosphate and its amine salt derivatives;

[0010] The alkali-resistant stabilizer includes polycarboxyl polyether and aliphatic amine;

[0011] The rust inhibitor includes dinonylnaphthalenesulfonate and alkenyl imidazoline succinate;

[0012] The demulsifier is a polyetheramine compound;

[0013] The base oil is a Class II or Class III hydrogenated neutral base oil.

[0014] Furthermore, the antioxidant is composed of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)isooctyl propionate and dialkyl dithiocarbamate in a mass ratio of 2:2:1.

[0015] Furthermore, the total content of the extreme pressure anti-wear agent accounts for 10-20% of the total mass of the composite agent, wherein the content of tricresyl phosphate is not less than 5%.

[0016] Furthermore, the total content of the rust inhibitor is 6-10%, and dinonylnaphthalenesulfonic acid amine and alkenyl imidazoline succinate are compounded in a mass ratio of 1:1.

[0017] Furthermore, the alkali-resistant stabilizer includes a combination of polyvinyl acrylate and aliphatic primary amine.

[0018] Furthermore, the base oil is a mixture of Formosa Plastics Group II 150N and 500N, wherein the mass ratio of 150N to 500N is 3:2.

[0019] Further, the following steps are included:

[0020] S1. Add an antioxidant to a reaction vessel and heat to 50-65°C;

[0021] S2. Under stirring conditions, add rust inhibitor, base oil, metal deactivator, extreme pressure anti-wear agent, demulsifier and alkali-resistant stabilizer in sequence;

[0022] S3. Continue stirring at a constant temperature of 50-65°C for 2-3 hours to allow all components to be fully dissolved and mixed;

[0023] S4, cooling and filtering to obtain a turbine oil compound;

[0024] Wherein, the antioxidant comprises at least two of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and dialkyldithiocarbamate;

[0025] The extreme pressure anti-wear agent comprises at least two of tricresyl phosphate, thiophosphate and its amine salt derivatives, and phosphate and its amine salt derivatives;

[0026] The alkali-resistant stabilizer includes polycarboxyl polyether and aliphatic amine;

[0027] The base oil is a Class II or Class III hydrogenated neutral base oil.

[0028] Furthermore, in step S1, the antioxidant is premixed and then heated, and the heating rate is controlled at 2-5°C / min.

[0029] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0030] First, the compound forms a complementary effect through a precisely proportioned ternary antioxidant system (including dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl) isooctyl propionate and dialkyl dithiocarbamate), effectively blocking the free radical chain reaction, significantly improving the oxidation stability of turbine oil in high temperature and high pressure working environments, extending the oil change cycle and reducing operation and maintenance costs.

[0031] Secondly, by introducing a compound system of tricresol phosphate, thiophosphate and its amine salt derivatives, a strong extreme pressure film layer is constructed, which enables the lubricating oil to have excellent anti-wear ability under high-load operating conditions, effectively reducing the surface wear of the friction pair and extending the service life of core components such as bearings and gears.

[0032] Thirdly, the present invention adopts a composite anti-rust system of dinonylnaphthalenesulfonic acid amine and alkenyl imidazoline succinate in terms of rust prevention, which can provide long-lasting protection for metal surfaces in oil-water coexistence and condensed water environments, significantly reduce the risk of corrosion, and improve the reliability and safety of equipment operation.

[0033] In addition, the polycarboxyl polyether and aliphatic amine alkali-resistant stabilizers introduced into the composite agent provide excellent resistance to alkaline water decomposition to address the problem of alkaline turbine condensate or residual alkaline treated water, effectively inhibiting metal soap deposition and oil emulsification failure, and are suitable for alkaline environments such as power plants, water utilities, and offshore platforms.

[0034] Finally, the combination of polyetheramine demulsifier and high-purity Class II / Class III hydrogenated base oil achieves excellent filtration performance and cleanliness of the oil, ensuring its stable operation in the precision high-speed rotor system. DETAILED DESCRIPTION

[0035] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0036] A long-life turbine oil for an ammonia-resistant steam turbine unit comprises the following components: an antioxidant, a rust inhibitor, an extreme pressure anti-wear agent, a metal deactivator, a demulsifier, an alkali-resistant stabilizer, and a base oil; wherein the antioxidant comprises at least two of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and dialkyldithiocarbamate; the extreme pressure anti-wear agent comprises at least two of tricresyl phosphate, thiophosphates and their amine salt derivatives, and phosphates and their amine salt derivatives; the alkali-resistant stabilizer comprises polycarboxyl polyether and aliphatic amines; the rust inhibitor comprises dinonylnaphthalenesulfonic acid amine and alkenyl imidazoline succinate; the demulsifier is a polyetheramine compound; and the base oil is a Class II or Class III hydrogenated neutral base oil.

[0037] This turbine oil additive significantly enhances the overall performance of lubricants through the synergistic action of multiple functional components. The three antioxidant components work synergistically to form a dual mechanism of chain termination and complexation protection, blocking free radical chain reactions and delaying oil oxidation. The extreme pressure anti-wear agent, using phosphate esters, forms a high-pressure film on the friction surface, enhancing lubrication protection. The alkali stabilizer chelates alkaline metal ions and forms a protective film, effectively resisting oil degradation caused by high-alkali vapors. The rust inhibitor and metal deactivator jointly inhibit oxidation and corrosion of metal surfaces. The demulsifier maintains oil-water separation and prevents emulsification failure. The base oil acts as a carrier to ensure stability under high-temperature and high-shear conditions.

[0038] This additive significantly enhances turbine oil's antioxidant, wear, rust, alkali resistance, and filterability, effectively extending equipment oil change intervals and improving operational reliability. It is particularly suitable for large-scale, high-temperature, high-load, and alkaline environments. Compared to conventional turbine oils, its ROT time is increased to over 900 minutes, its four-ball test PB value is raised to over 100 kg, its wet filterability is greater than 90, and its corrosion resistance reaches Class 1.

[0039] In a possible embodiment, the antioxidant is composed of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and dialkyldithiocarbamate in a mass ratio of 2:2:1.

[0040] The three-component antioxidant compound forms a synergistic stabilization system, which plays a role in the initial oxidation stage (capturing free radicals), the high temperature stage (terminating chain reaction) and the metal-mediated stage (complexing metal ions), thereby enhancing the antioxidant effect.

[0041] After the compounding ratio is optimized, the ROT time of the rotating oxygen bomb method is significantly improved, which is more than 20% higher than that of a single component or any two-component method. It is suitable for high-temperature and long-cycle operation scenarios to ensure the stability of the lubrication system.

[0042] In a possible embodiment, the total content of the extreme pressure and anti-wear agent accounts for 10-20% of the total mass of the composite agent, wherein the content of tricresyl phosphate is not less than 5%.

[0043] Tricresol phosphate forms a chemical adsorption film and an extreme pressure film on the surface of the high-pressure shear friction pair, improving the boundary lubrication performance. Other phosphate esters and their amine salt derivatives supplement its thermal stability and film integrity.

[0044] The wear spot diameter is controlled within 0.30-0.35mm, and the PB value is stably over 100kg, meeting the operating requirements of heavy-load steam turbine systems and effectively extending the service life of sliding parts.

[0045] In a possible implementation manner, the total content of the rust inhibitor is 6-10%, and dinonylnaphthalenesulfonic acid amine and alkenyl imidazoline succinate are compounded in a mass ratio of 1:1.

[0046] The two form an adsorption layer and a passivation film at the oil-water interface and the metal surface respectively, effectively blocking the effects of water vapor and oxygen, and enhancing multiple anti-rust capabilities.

[0047] No rust spots were generated in the wet heat salt spray test, and the rust resistance level reached Grade A in the GB / T 11143 standard, making it particularly suitable for humid coastal areas and environments rich in condensation water.

[0048] In one possible embodiment, the alkali-resistant stabilizer includes a combination of polyvinyl acrylate and aliphatic primary amine.

[0049] Polycarboxylates provide multifunctional chelating sites to adsorb alkaline species, and aliphatic primary amines form an alkaline buffer film layer and inhibit the formation of metal soaps, jointly delaying the decomposition and degradation of oils due to the intrusion of alkaline water.

[0050] The color, acid value and precipitation index of the oil under alkaline conditions are significantly better than those of conventional formulas, and the alkaline working life is increased by at least 30%. It can be used in the alkaline water cooling system of turbines.

[0051] In one possible embodiment, the base oil is a mixture of Formosa Plastics Group II 150N and 500N, wherein the mass ratio of 150N to 500N is 3:2.

[0052] Through the coordinated regulation of medium and low viscosity oils, the viscosity stability of the base oil is maintained between high and low temperatures, the fluidity is improved while maintaining the strength of the lubricating film.

[0053] The improved oil exhibits excellent kinematic viscosity and shear stability at both -20°C and 100°C, meeting all-weather operation requirements.

[0054] In one possible embodiment, the preparation method of the turbine oil compound includes the following steps: S1, adding an antioxidant to a reaction vessel and heating to 50-65°C; S2, adding a rust inhibitor, a base oil, a metal deactivator, an extreme pressure anti-wear agent, a demulsifier and an alkali stabilizer in sequence under stirring conditions; S3, continuing to maintain a constant temperature of 50-65°C and stirring for 2-3 hours; S4, cooling and filtering.

[0055] Through step-by-step addition and constant temperature stirring processes, we ensure that all kinds of functional additives are fully dissolved and evenly dispersed in the system, avoiding excessive concentration or ineffectiveness of local components.

[0056] Improve the batch consistency and long-term stability of the composite agent. There is no obvious stratification, precipitation or bubbles between the components of the composite agent, which is suitable for industrial batch preparation.

[0057] In a possible embodiment, in step S1, the antioxidant is premixed and then heated, and the heating rate is controlled at 2-5° C. / min.

[0058] Slow heating helps the antioxidants to dissolve in each other and prevents thermal degradation and foaming caused by rapid heating.

[0059] Ensure the integrity of the structure of the antioxidant active ingredients, improve its oxidation induction period index, and enhance the stability of the final oil product.

[0060] To validate the performance of the turbine oil additive package of the present invention, a systematic experiment was designed and conducted. A 46# turbine oil sample was prepared with the additive package. Its antioxidant, anti-wear, rust-proof, alkali resistance, and filterability were tested. The results were compared with those of a typical commercially available product in the prior art to ensure comparability and reproducibility.

[0061] 1. Antioxidant performance test

[0062] The oxidation induction period of each sample was tested using the SH / T 0193-2008 "Determination of Oxidative Stability of Lubricating Oils (Rotating Oxygen Bomb Method)." The antioxidant was added to the composite system according to the ratio (2:2:1) described in claim 2. The lubricating oil was prepared using the above-described preparation method and subjected to a rotating oxygen bomb test. The test results showed that Example A's oxidation induction time was 930 minutes, significantly exceeding the 680 minutes of the control sample, an improvement of 36.8%, demonstrating that this antioxidant formulation exhibits significant synergistic antioxidant activity.

[0063] 2. Anti-wear performance test

[0064] The extreme pressure properties of the oils were tested using the SH / T 0204-2009 "Determination of Antiwear Performance of Lubricating Oils (Four-Ball Method)" test. The experimental conditions were a load of 392 N, a temperature of 75°C, a rotational speed of 1200 r / min, and a test duration of 60 minutes. The wear spot diameter and PB value were recorded. The wear spot diameter of Example A was 0.31 mm, and the PB value was 106 kg. The wear spot diameter of the comparative sample was 0.46 mm, and the PB value was 84 kg. These results demonstrate that the composite agent of the present invention effectively enhances the antiwear protection of lubricating oils under high loads.

[0065] 3. Anti-rust performance test

[0066] The rust-preventive properties of lubricants were tested in a hot and humid environment using the standard GB / T 11143-2008, "Petroleum Products, Steel Sheet Rust Test (Aqueous Solution Method)." Example A, using a 1:1 mixture of dinonylnaphthalenesulfonic acid amine and alkenyl imidazoline succinate, showed "rust-free" (rust level 0). The control sample, however, showed slight rust (rust level 1). This demonstrates that the composite rust inhibitor system significantly improves the corrosion resistance of lubricants, making it particularly suitable for steam turbine systems operating in humid environments or those containing condensate.

[0067] 4. Alkali resistance evaluation

[0068] The stability of the oil after 72 hours was assessed by artificially simulating an alkaline environment (adding 0.2 wt% NaOH solution to the oil). This included changes in appearance, precipitation, acid value, and color. Example A showed no precipitation or phase separation, maintained essentially unchanged color, and had an acid value change of no more than 0.02 mg KOH / g. The control sample exhibited significant turbidity and precipitation, with an acid value increase of 0.12 mg KOH / g. These results demonstrate that the polycarboxyl polyether and aliphatic amine alkali-resistant agents introduced in the present invention provide significant stability support under high-alkaline conditions.

[0069] 5. Filtration performance test

[0070] According to SH / T 0805-2010, "Lubricating Oil Filterability Test Method," both dry and wet filterability were tested. Example A showed a dry filterability of 92% and a wet filterability of 88%, while the control sample showed 84% and 65%, respectively. These experimental results demonstrate that the demulsifier of the present invention has a good ratio with the base oil, effectively maintaining the oil's filterability in aqueous environments and is suitable for precision steam turbine equipment.

[0071] The above experimental data verify that the turbine oil compound of the present invention is superior to the comparative product in multiple key performance indicators, reflecting its comprehensive advantages in anti-oxidation, anti-wear, anti-rust, alkali resistance and filtration.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A long-life turbine oil for an ammonia-resistant steam turbine unit, characterized in that: Contains the following components: antioxidant, rust inhibitor, extreme pressure anti-wear agent, metal deactivator, demulsifier, alkali stabilizer and base oil; Wherein, the antioxidant comprises at least two of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and dialkyldithiocarbamate; The extreme pressure anti-wear agent comprises at least two of tricresyl phosphate, thiophosphate and its amine salt derivatives, and phosphate and its amine salt derivatives; The alkali-resistant stabilizer includes polycarboxyl polyether and aliphatic amine; The rust inhibitor includes dinonylnaphthalenesulfonate and alkenyl imidazoline succinate; The demulsifier is a polyetheramine compound; The base oil is a Class II or Class III hydrogenated neutral base oil.

2. The turbine oil according to claim 1, characterized in that The antioxidant is prepared by compounding dinonyldiphenylamine, beta-(3,5-di-tert-butyl-4-hydroxyphenyl)isooctyl propionate and dialkyl dithiocarbamate in a mass ratio of 2:2:

1.

3. The turbine oil according to claim 1, characterized in that The total content of the extreme pressure anti-wear agent accounts for 10-20% of the total mass of the composite agent, wherein the content of tricresyl phosphate is not less than 5%.

4. The turbine oil according to claim 1, characterized in that The total content of the rust inhibitor is 6-10%, and dinonylnaphthalenesulfonic acid amine and alkenyl imidazoline succinate are compounded in a mass ratio of 1:

1.

5. The turbine oil according to claim 1, characterized in that The alkali-resistant stabilizer comprises a combination of polyvinyl acrylate and aliphatic primary amine.

6. The turbine oil according to claim 1, characterized in that The base oil is a mixture of Formosa Plastics Group II 150N and 500N, wherein the mass ratio of 150N to 500N is 3:

2.

7. A method for preparing a turbine oil compound, characterized in that: The steps include: S1. Add an antioxidant to a reaction vessel and heat to 50-65°C; S2. Under stirring conditions, add rust inhibitor, base oil, metal deactivator, extreme pressure anti-wear agent, demulsifier and alkali-resistant stabilizer in sequence; S3. Continue stirring at a constant temperature of 50-65°C for 2-3 hours to allow all components to be fully dissolved and mixed; S4, cooling and filtering to obtain a turbine oil compound; Wherein, the antioxidant comprises at least two of dinonyldiphenylamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and dialkyldithiocarbamate; The extreme pressure anti-wear agent comprises at least two of tricresyl phosphate, thiophosphate and its amine salt derivatives, and phosphate and its amine salt derivatives; The alkali-resistant stabilizer includes polycarboxyl polyether and aliphatic amine; The base oil is a Class II or Class III hydrogenated neutral base oil.

8. The preparation method according to claim 7, wherein in step S1, the antioxidant is premixed and then heated, and the heating rate is controlled at 2-5°C / min. 9 . The preparation method according to claim 7 , wherein the order of adding the components in step S2 is: rust inhibitor, base oil, metal deactivator, extreme pressure anti-wear agent, demulsifier, and alkali-resistant stabilizer.

10. The preparation method according to claim 7, wherein the filtration in step S4 is performed by using a 5-10 μm microporous filter element for precision filtration.