Lubricating oil for yaw and pitch reducer of wind turbine generator set and preparation method thereof

Abstract

The present invention relates to the technical field of lubrication of wind turbine gearboxes, and in particular to a lubricating oil for a yaw-pitch speed reducer of a wind turbine and a preparation method thereof. The lubricating oil comprises, by weight, 49-53 parts of metallocene polyalphaolefin, 23-28 parts of a functional fluid containing a low-viscosity and low-volatility polyalphaolefin base material, 15-20 parts of alkyl naphthalene, 2.5-3.0 parts of a composite additive package, 2-5 parts of an oiliness agent, 0.005-0.01 parts of a demulsifier, 0.02-0.03 parts of a defoamer, and 0.005-0.01 parts of a pour point depressant. The lubricating oil for a yaw-pitch speed reducer of a wind turbine according to the present invention has excellent high and low temperature performance, antioxidant performance, additive sensitivity, and foam stability; and the transmission energy efficiency is higher, and has an excellent energy-saving effect.

Description

Technical Field

[0001] The invention relates to lubricating oil for a yaw and pitch-changing reducer of a wind generator set and a preparation method thereof, belonging to the technical field of lubrication of a gearbox of a wind generator set. Background Art

[0002] Wind power generation is a way of generating electricity by converting the kinetic energy of wind into electrical energy. Wind energy is a clean, pollution-free, renewable energy source. China is rich in wind energy resources, with about 1 billion kW of exploitable wind energy reserves, and the prospects for wind power generation are broad. China's wind power installed capacity has ranked first in the world for 14 consecutive years. Under the general trend of carbon peak and carbon neutrality, the proportion of wind power installed capacity and wind power penetration rate will continue to increase in the future, and there is huge room for development.

[0003] China has a vast territory, but wind-rich areas are mostly located in high-latitude and high-altitude areas, such as Northeast China, Inner Mongolia, Gansu, Xinjiang, etc. The winter temperature may drop to below -40℃, and the operating conditions are relatively harsh, which is not conducive to the maintenance of wind farm equipment. With the large-scale offshore expansion of Chinese wind power companies, high-latitude central and northern Asian plateaus, Gobi and deep sea projects are constantly being built, and the overall operating environment of these wind farms is also relatively harsh. This requires that the various subsystems of wind turbines can also operate reliably in low-temperature environments.

[0004] A complete set of wind turbine generator sets consists of foundation, tower, nacelle and wind rotor. The core systems include pitch system, yaw system, main gearbox and generator. Among them, the pitch system, as an important actuator for the control and protection of wind turbines, plays a vital role in the safe, stable and efficient operation of wind turbines. The pitch system mainly adjusts the power of wind turbines by changing the blade angle of the wind turbine to adapt to the changing wind speed. When the wind speed is below the rated wind speed, the blades are fully opened to capture wind energy to the maximum extent; when the wind speed is above the rated wind speed, the blade angle is adjusted according to the instructions of the main controller to ensure the output power of the unit. When the safe wind speed is exceeded or the machine is shut down due to a fault or emergency, the blades are rotated to a safe position to protect the wind turbine and realize the safe parking function. The main driving device of the pitch system is the pitch reduction gearbox, which transmits torque to the pitch gear through the reduction gearbox to drive each blade to rotate to a precise angle. The core of the yaw system is the yaw drive device, which includes a motor, a reduction gearbox and an open gear transmission pair, which is installed on the main frame through a flange connection. The functions of the yaw system include: according to the change of wind direction, the yaw operating device sends instructions according to the system control unit to put the wind rotor in a windward state to improve the power generation efficiency of the wind turbine; the yaw system should also provide the necessary locking torque to ensure the safe operation of the unit and the needs of the shutdown state.

[0005] Both the variable pitch reduction gearbox and the yaw reduction gearbox need to lubricate the reduction gears. The current lubrication scheme generally adopts the same formula system as the main gearbox, and the viscosity is selected as ISO VG 320, 220 or 150 grade mineral, semi-synthetic or fully synthetic gear oil. However, as more and more wind farms operate in low-temperature environments such as high latitudes, high altitudes, and deep seas, the above-mentioned general gear oils increase in viscosity and become less fluid as the ambient temperature drops, and cannot meet the operation and lubrication requirements of -30℃ to -40℃ or even lower ambient temperatures. In such a low-temperature and harsh environment, the operating conditions are complex and changeable, and the variable pitch and yaw systems need to be started frequently. If the gear oil is viscous and the fluidity is poor at low temperatures, it will cause the reduction gearbox of the core device to lag or even stop moving, which will affect the power generation efficiency of the unit at the least, and it is very easy to fail and cause shutdown. Statistics show that the failure rate of the variable pitch system is as high as 21.29%, causing the downtime of wind turbines to account for as much as 23.32%. The fluidity of the oil deteriorates, it takes longer to replace the oil and parts, and the cost of troubleshooting and maintenance is extremely high.

[0006] In view of the shortcomings of existing variable pitch and yaw reduction gearbox lubricants, a lubricant with better low-temperature fluidity and low-temperature lubrication performance in low-temperature and ultra-low-temperature operating environments is needed to ensure the normal operation of the variable pitch system and yaw system under low-temperature conditions; at the same time, this lubricant should also have thermal stability and lubricating oil film strength in the high-temperature working range to ensure lubrication protection of the variable pitch and yaw gearboxes in the high-temperature season in summer. This comprehensive lubrication capability across high and ultra-low temperatures will not only provide lubrication protection for the variable pitch and yaw systems, but also improve unit efficiency and bring energy-saving effects. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a lubricating oil for a yaw and pitch control reducer of a wind turbine generator set and a preparation method thereof. The lubricating oil has excellent high and low temperature performance and lubrication and anti-wear performance, and has higher transmission energy efficiency and excellent energy-saving effect; it has excellent cleaning and high temperature resistance properties, as well as excellent foam stability and longer service life.

[0008] The technical solution of the present invention to solve the above technical problems is as follows:

[0009] A lubricating oil for a yaw and pitch control reducer of a wind turbine generator set, the lubricating oil comprising: metallocene polyalphaolefin, a functional fluid containing a polyalphaolefin base material with low viscosity and low volatility, alkyl naphthalene, a composite additive package, an oiliness agent, a demulsifier, a defoamer and a pour point depressant;

[0010] The weight ratio of the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material and the alkyl naphthalene is (1.15-1.80): 1;

[0011] The weight ratio of the metallocene polyalphaolefin to the alkyl naphthalene is (2.4-3.0):1.

[0012] Furthermore, the lubricating oil comprises, by weight, 49-53 parts of metallocene polyalphaolefin, 23-28 parts of functional fluid containing a low-viscosity, low-volatility polyalphaolefin base material, 15-20 parts of alkyl naphthalene, 2.5-3.0 parts of a composite additive package, 2-5 parts of an oiliness agent, 0.005-0.01 parts of a demulsifier, 0.02-0.03 parts of a defoaming agent, and 0.005-0.01 parts of a pour point depressant.

[0013] Furthermore, the mass ratio of the alkyl naphthalene to the oiliness agent is (3-10):1.

[0014] Further, the metallocene polyalphaolefin is MPAO150;

[0015] The functional fluid containing a low-viscosity, low-volatility poly-alpha-olefin base material is oligomeric alpha-olefin MAX3.5;

[0016] The alkyl naphthalene has a kinematic viscosity of 20-100 cst at 40°C.

[0017] Furthermore, the composite additive package is HITEC 307.

[0018] Furthermore, the oiliness agent is at least one of polyester and fatty acid ester.

[0019] Furthermore, the demulsifier is at least one of polyethylene glycol fatty acid ester and ethylene oxide-propylene oxide block copolymer;

[0020] The defoaming agent is at least one of an organic silicon defoaming agent and a non-silicon defoaming agent.

[0021] Furthermore, the pour point depressant is a polymethacrylate polymer.

[0022] The present invention also discloses a method for preparing lubricating oil for a yaw and pitch control reducer of a wind turbine generator set, the preparation method comprising:

[0023] S1, adding metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, heating and stirring evenly;

[0024] S2, adding composite additives, oiliness agent, pour point depressant, demulsifier and defoamer into the blending kettle in sequence and mixing evenly;

[0025] S3. After the blending is completed, the lubricating oil is filtered using a filter bag with a filter diameter not greater than 15 μm to obtain the lubricating oil for the yaw and pitch control reducer of the wind turbine generator set.

[0026] The beneficial effects of the present invention are:

[0027] The lubricating oil for the yaw and pitch reducer of the wind turbine generator set of the present invention has excellent high and low temperature performance, antioxidant performance, additive sensitivity, and foam stability; excellent low temperature fluidity, which meets the requirements of pumping and lubrication at low temperatures; good heat dissipation performance, which can quickly take away the heat generated during the movement of the gears; excellent high temperature performance, strong shear resistance, good viscosity retention performance, stable oil film, and good lubricity; continuous and stable oil film, which slows down gear vibration, reduces gear impact, and moves more smoothly; excellent extreme pressure and anti-wear performance, with extremely high load-bearing capacity, reduces tooth surface wear, and evenly distributes loads; excellent foam stability, which can meet the anti-foaming requirements of wind power gears for ultra-long life, and can also effectively prevent cavitation of gear components; higher viscosity-temperature characteristics, higher transmission energy efficiency, and excellent energy-saving effects; excellent cleaning and high temperature resistance characteristics, and long service life. The excellent performance of the present invention can also meet the lubrication needs of the main gearbox of the wind turbine generator set.

[0028] In the lubricating oil for the yaw and pitch speed reducer of the wind turbine generator set described in the present invention, the alkyl naphthalene base oil has extremely excellent antioxidant performance, hydrolysis stability, excellent additive solubility and dispersibility. The electron-rich naphthalene ring in the alkyl naphthalene base oil can absorb oxygen, thereby interrupting the transmission of the oxidation chain, preventing the continued oxidation of hydrocarbons, and preventing the occurrence of oxidation. The electron-rich naphthalene ring structure of alkyl naphthalene has both a lower aniline point and a stronger polarity, and has good solubility and dispersibility for polar additives. The special electron-rich naphthalene ring structure of alkyl naphthalene and the regular saturated hydrocarbon structure will form a mutual synergistic effect, which can not only give play to the high saturation and excellent high-temperature oxidation resistance of the saturated alkane structure, but also have the strong polarity and water resistance of alkyl naphthalene. The present invention selects alkyl naphthalene base oil and alpha olefin polymers in different polymerization forms as the base oil combination to achieve the best beneficial effect.

[0029] Metallocene polyalphaolefins are obtained by polymerizing alpha olefins using metallocene catalysts. Compared with traditional polyalphaolefins, metallocene polyalphaolefins have higher viscosity index, better shear stability, better oxidation stability, better air release and other outstanding properties. The electron-rich naphthalene ring structure of alkyl naphthalene base oil forms a synergistic effect with the saturated hydrocarbon structure of metallocene polyalphaolefins, which can not only give full play to the highly saturated oxidation resistance of metallocene polyalphaolefins, but also have the strong polarity and water resistance of alkyl naphthalene. The synergistic effect of alkyl naphthalene and the saturated alkane structure of metallocene polyalphaolefins is shown in the following structural formula:

[0030] .

[0031] The electron-rich naphthalene ring structure of alkyl naphthalene base oil also has a synergistic effect with the functional fluid containing low viscosity and low volatility polyalphaolefin base stocks, which can not only exert the highly saturated oxidation resistance of saturated hydrocarbons, but also have the strong polarity and water resistance of alkyl naphthalene. The synergistic effect of alkyl naphthalene and the functional fluid containing low viscosity and low volatility polyalphaolefin base stocks is shown below, where R is n-butyl, n-hexyl, n-octyl, n-decyl or n-dodecyl.

[0032] .

[0033] In addition, a reasonable proportion of the oiliness agent and the alkyl naphthalene can produce a better synergistic effect, so that the lubricating oil for the yaw and pitch reducer of the wind turbine generator set has good anti-wear performance and good hydrolysis resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the test principle diagram of MTM micro traction test machine;

[0035] Figure 2 This is the test result diagram of MTM micro traction test machine. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0038] A lubricating oil for a yaw and pitch reducer of a wind turbine generator set, characterized in that the lubricating oil comprises: metallocene polyalphaolefin, a functional fluid containing a polyalphaolefin base material with low viscosity and low volatility, alkyl naphthalene, a composite additive package, an oiliness agent, a demulsifier, a defoamer and a pour point depressant.

[0039] Specifically, in parts by weight, the lubricating oil includes: 49-53 parts of metallocene polyalphaolefin, 23-28 parts of functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, 15-20 parts of alkyl naphthalene, 2.5-3.0 parts of composite additive package, 2-5 parts of oiliness agent, 0.005-0.01 parts of demulsifier, 0.02-0.03 parts of defoamer, and 0.005-0.01 parts of pour point depressant.

[0040] Specifically, the weight ratio of the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material and the alkyl naphthalene is (1.15-1.80): 1;

[0041] The weight ratio of the metallocene polyalphaolefin to the alkyl naphthalene is (2.4-3.0):1.

[0042] Specifically, the mass ratio of the alkyl naphthalene to the oiliness agent is (3-10):1.

[0043] Specifically, the metallocene polyalphaolefin is the metallocene polyalphaolefin MPAO150 produced by ExxonMobil Chemical, Chevron Phillips, INEOS, and Sinopec Maoming;

[0044] The functional fluid containing a low-viscosity and low-volatility poly-alpha olefin base material is oligomeric alpha olefin MAX3.5 produced by ExxonMobil Chemical;

[0045] The alkyl naphthalene having a kinematic viscosity of 20-100 cst at 40° C. is selected from the alkyl naphthalene produced by ExxonMobil Chemical, Kings Chemical, and Doppler Chemical.

[0046] Specifically, the composite additive package is HITEC 307 produced by Afton Chemical.

[0047] Specifically, the oiliness agent is at least one of polyester and fatty acid ester, which improves the additive sensitivity and balance of oil products and increases the synergistic effect between different base oils, different additives, and base oils and additives.

[0048] Specifically, the demulsifier is at least one of polyethylene glycol fatty acid ester and ethylene oxide-propylene oxide block copolymer; it is adsorbed on the oil-water interface to change the interfacial tension between oil and water, or adsorbed on the emulsifier to destroy the hydrophilic-lipophilic balance, so that the emulsion is separated from the oil and water during the phase transition process.

[0049] The defoamer is at least one of an organic silicon defoamer and a non-silicon defoamer. Preferably, the defoamer is a compound of an organic silicon defoamer and a non-silicon defoamer; more specifically, the defoamer is a compound of dimethyl silicone oil and polyacrylate, which is adsorbed on the foam film in the form of highly dispersed colloidal particles, and the film is thinned until it breaks by reducing surface tension, expanding, etc., to achieve the purpose of defoaming.

[0050] Specifically, the pour point depressant is a polymethacrylate polymer, preferably 1-248 and 1-254 produced by Evonik. The pour point depressant can form a eutectic with wax in the oil at low temperature to change its shape and size, improve the low temperature flow properties of the oil, and reduce energy loss.

[0051] A method for preparing lubricating oil for a yaw and pitch reducer of a wind turbine generator set, the preparation method comprising:

[0052] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir while heating, the stirring speed is 60-100r / min, the temperature is raised to 50-65°C, and stir for 1 hour;

[0053] (2) Add the composite additives into the blending kettle, maintain the temperature at 50-65°C and the stirring speed at 60-100 r / min, and stir for 40 minutes;

[0054] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 50-65°C and the stirring speed at 60-100 r / min, and stir for 40 minutes;

[0055] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 50-65°C and the stirring speed at 60-100 r / min, and stir for 60 min.

[0056] (5) Maintaining a temperature of 50-50-65°C and a stirring speed of 60-100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0057] (6) After the blending is completed, the lubricating oil is filtered at a pressure of 0.1 MPa to 0.2 MPa using a filter bag with a filter diameter not greater than 15 μm to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0058] Example 1

[0059] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 1 below.

[0060] Table 1 Formula composition of Example 1

[0061]

[0062] The preparation method is:

[0063] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir and heat at a stirring speed of 100 r / min, raise the temperature to 65°C, and stir for 1 hour;

[0064] (2) Add the composite additives into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0065] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0066] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 60 min.

[0067] (5) Maintaining the temperature at 65°C and the stirring speed at 100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0068] (6) After the blending is completed, the lubricating oil is filtered at a pressure of 0.2 MPa using a filter bag with a filter diameter of no more than 15 μm to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0069] Example 2

[0070] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 2 below.

[0071] Table 2 Formula composition of Example 2

[0072]

[0073] The preparation method is:

[0074] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir while heating, the stirring speed is 60r / min, the temperature is raised to 50°C, and stirred for 1 hour;

[0075] (2) Add the composite additives into the blending kettle, maintain the temperature at 50°C and the stirring speed at 60 r / min, and stir for 40 min;

[0076] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 50°C and the stirring speed at 60 r / min, and stir for 40 minutes;

[0077] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 50°C and the stirring speed at 60 r / min, and stir for 60 min.

[0078] (5) Maintaining the temperature at 50°C and the stirring speed at 60 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0079] (6) After the blending is completed, the mixture is filtered using a filter bag with a filter diameter of no more than 15 μm at a pressure of 0.1 MPa to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0080] Example 3

[0081] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 3 below.

[0082] Table 3 Formula composition of Example 3

[0083]

[0084] The preparation method is:

[0085] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir and heat at a stirring speed of 100 r / min, raise the temperature to 65°C, and stir for 1 hour;

[0086] (2) Add the composite additives into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0087] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0088] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 60 min.

[0089] (5) Maintaining the temperature at 65°C and the stirring speed at 100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0090] (6) After the blending is completed, the mixture is filtered using a filter bag with a filter diameter of no more than 15 μm at a pressure of 0.2 MPa to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0091] Example 4

[0092] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 4 below.

[0093] Table 4 Formula composition of Example 4

[0094]

[0095] The preparation method is:

[0096] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir and heat at a stirring speed of 100 r / min, raise the temperature to 65°C, and stir for 1 hour;

[0097] (2) Add the composite additives into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0098] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0099] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 60 min.

[0100] (5) Maintaining the temperature at 65°C and the stirring speed at 100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0101] (6) After the blending is completed, the mixture is filtered using a filter bag with a filter diameter of no more than 15 μm at a pressure of 0.1 MPa to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0102] Example 5

[0103] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 5 below.

[0104] Table 5 Formula composition of Example 5

[0105]

[0106] The preparation method is:

[0107] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir and heat at a stirring speed of 100 r / min, raise the temperature to 65°C, and stir for 1 hour;

[0108] (2) Add the composite additives into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0109] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0110] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 60 min.

[0111] (5) Maintaining the temperature at 65°C and the stirring speed at 100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0112] (6) After the blending is completed, the mixture is filtered using a filter bag with a filter diameter of no more than 15 μm at a pressure of 0.2 MPa to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0113] Example 6

[0114] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 6 below.

[0115] Table 6 Formula composition of Example 6

[0116]

[0117] The preparation method is:

[0118] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir while heating, the stirring speed is 60r / min, the temperature is raised to 50°C, and stirred for 1 hour;

[0119] (2) Add the composite additives into the blending kettle, maintain the temperature at 50°C and the stirring speed at 60 r / min, and stir for 40 min;

[0120] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 50°C and the stirring speed at 60 r / min, and stir for 40 minutes;

[0121] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 50°C and the stirring speed at 60 r / min, and stir for 60 min.

[0122] (5) Maintaining the temperature at 50°C and the stirring speed at 60 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0123] (6) After the blending is completed, the mixture is filtered using a filter bag with a filter diameter of no more than 15 μm at a pressure of 0.2 MPa to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0124] Example 7

[0125] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 7 below.

[0126] Table 7 Formula composition of Example 7

[0127]

[0128] The preparation method is:

[0129] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir and heat at a stirring speed of 100 r / min, raise the temperature to 65°C, and stir for 1 hour;

[0130] (2) Add the composite additives into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0131] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0132] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 60 min.

[0133] (5) Maintaining the temperature at 65°C and the stirring speed at 100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0134] (6) After the blending is completed, the lubricating oil is filtered at a pressure of 0.2 MPa using a filter bag with a filter diameter of no more than 15 μm to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0135] Example 8

[0136] The formula composition of the lubricating oil for the yaw and pitch reducer of the wind turbine generator set in this embodiment is shown in Table 8 below.

[0137] Table 8 Formula composition of Example 8

[0138]

[0139] The preparation method is:

[0140] (1) Add metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, stir and heat at a stirring speed of 100 r / min, raise the temperature to 65°C, and stir for 1 hour;

[0141] (2) Add the composite additives into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0142] (3) Add the oiliness agent into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 40 min;

[0143] (4) Add the pour point depressant into the blending kettle, maintain the temperature at 65°C and the stirring speed at 100 r / min, and stir for 60 min.

[0144] (5) Maintaining the temperature at 65°C and the stirring speed at 100 r / min, add the demulsifier and defoamer into the blending kettle and continue stirring and blending for 2 hours.

[0145] (6) After the blending is completed, the lubricating oil is filtered at a pressure of 0.2 MPa using a filter bag with a filter diameter of no more than 15 μm to obtain the lubricating oil for the yaw and pitch reducer of the wind turbine generator set.

[0146] Comparative Example 1

[0147] The lubricating oil for the yaw and pitch reducer of a wind turbine generator set was prepared by the same method as in Example 1, except that no alkyl naphthalene was added. The specific formula composition is shown in Table 9 below.

[0148] Table 9 Formula composition of comparative example 1

[0149]

[0150] Comparative Example 2

[0151] The lubricating oil for the yaw and pitch reducer of a wind turbine generator set was prepared by the same method as in Example 1, except that the functional fluid containing a low-viscosity and low-volatility poly-alpha-olefin base material was not added. The specific formula composition is shown in Table 10 below.

[0152] Table 10 Formula composition of comparative example 2

[0153]

[0154] Comparative Example 3

[0155] The lubricating oil for the yaw and pitch reducer of a wind turbine generator set was prepared by the same method as in Example 1, except that no metallocene polyalphaolefin was added. The specific formula composition is shown in Table 11 below.

[0156] Table 11 Formula composition of comparative example 3

[0157]

[0158] Comparative Example 4

[0159] The lubricating oil for the yaw and pitch reducer of a wind turbine is prepared by the same method as in Example 1, except that: the dosage ratio of alkyl naphthalene is reduced so that the weight ratio of the functional fluid containing the low-viscosity and low-volatility polyalphaolefin base material and alkyl naphthalene is 2:1; the weight ratio of the metallocene polyalphaolefin and alkyl naphthalene is 3.35:1; the specific formula composition is shown in Table 12 below.

[0160] Table 12 Formula composition of comparative example 4

[0161]

[0162] Comparative Example 5

[0163] The lubricating oil for the yaw and pitch reducer of a wind turbine is prepared by the same method as in Example 1, except that: the dosage ratio of alkyl naphthalene is increased so that the weight ratio of the functional fluid containing the low-viscosity and low-volatility polyalphaolefin base material and alkyl naphthalene is 0.93:1; the weight ratio of the metallocene polyalphaolefin and alkyl naphthalene is 1.24:1; the specific formula composition is shown in Table 13.

[0164] Table 13 Formula composition of comparative example 5

[0165]

[0166] Comparative Example 6

[0167] The lubricating oil for the yaw and pitch reducer of a wind turbine generator set is prepared by the same method as in Example 1, except that the amount of the oiliness agent is increased. The specific formula composition is shown in Table 14 below.

[0168] Table 14 Formula composition of comparative example 6

[0169]

[0170] Comparative Example 7

[0171] The lubricating oil for the yaw and pitch reducer of a wind turbine generator set is prepared by the same method as in Example 1, except that the amount of the oiliness agent is reduced. The specific formula composition is shown in Table 15 below.

[0172] Table 15 Formula composition of comparative example 7

[0173]

[0174] Comparative Example 8

[0175] Purchase commercially available wind turbine yaw and pitch reducer lubricating oil.

[0176] The lubricating oils prepared in the above examples and comparative examples were subjected to performance tests, and the specific test results are shown in Tables 16 and 17. The test methods involved are:

[0177] Kinematic viscosity: ASTM D445;

[0178] Viscosity index: ASTM D2270;

[0179] Flash point: ASTM D92;

[0180] Pour point: ASTM D97;

[0181] Copper corrosion: ASTM D130;

[0182] Maximum sintering load PD: ASTM D2596;

[0183] Wear spot diameter D: ASTM D2266

[0184] Brookfield viscosity: ASTM D2983;

[0185] Oxidation stability test: ASTM D2893

[0186] Low temperature dynamic viscosity: GB / T 6538-2010;

[0187] Low temperature pumping viscosity: GB / T 9171-88;

[0188] Flender foam properties: ISO 12152.

[0189] Table 16 Lubricant performance test data in Examples 1-8

[0190]

[0191] Table 17 Lubricant performance test data in Comparative Examples 1-8

[0192]

[0193] From the above table data, it can be seen that the lubricating oil for the yaw and pitch reducer of the wind turbine generator set prepared by the preparation method of the present invention in Examples 1-8 has a higher viscosity index, a higher flash point, a lower pour point, and better low-temperature fluidity, and can completely replace the existing lubricating oil for the yaw and pitch reducer of the wind turbine generator set, and can provide a lower operating temperature and better energy-saving effect. In summary, the low-temperature energy-saving lubricating oil for the yaw and pitch reducer of the wind turbine generator set and the preparation method thereof provided by the present invention have the following advantages:

[0194] a) Excellent low-temperature fluidity, meeting the requirements of pumping and lubrication at low temperatures;

[0195] b) Good heat dissipation performance, which can quickly take away the heat generated during the movement of the gears;

[0196] c) Excellent high temperature performance, strong shear resistance, good viscosity retention, stable oil film and good lubricity;

[0197] d) The oil film is continuous and stable, which reduces gear vibration, reduces gear impact, and makes the movement smoother;

[0198] e) Excellent extreme pressure and anti-wear performance, extremely high load-bearing capacity, reduced tooth surface wear, and evenly distributed load;

[0199] f) Higher viscosity-temperature characteristics, higher transmission energy efficiency, and excellent energy-saving effect;

[0200] g) Excellent cleaning and high temperature resistance characteristics, long service life.

[0201] In addition, from the comparison of the data of Example 1 and Examples 7-8, it can be seen that when the defoaming agent is a combination of an organosilicon defoaming agent and a non-silicon defoaming agent, it is more conducive to the continuous control of the foam.

[0202] From the comparison of the data of Example 1 and Comparative Example 1, it can be seen that if alkyl naphthalene is not added to the formula composition, the appearance is a brown-yellow hazy liquid. After being stored for one week, white sludge-like precipitation is precipitated at the bottom, and the formula system is incompatible.

[0203] From the comparison of the data of Example 1 and Comparative Example 2, it can be seen that if the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material is not added to the formulation, the low-temperature performance will be greatly reduced.

[0204] From the comparison of the data of Example 1 and Comparative Example 3, it can be seen that if metallocene polyalphaolefin is not added to the formulation, the high temperature performance and anti-wear ability will be greatly reduced.

[0205] From the comparison of the data of Example 1 and Comparative Example 4, it can be seen that if the proportion of alkyl naphthalene in the formulation is reduced, both the low temperature performance and the anti-wear ability will be affected.

[0206] From the comparison of the data of Example 1 and Comparative Example 5, it can be seen that if the proportion of alkyl naphthalene in the formulation is increased, the viscosity-temperature performance, low-temperature performance and anti-wear ability will be affected.

[0207] From the comparison of the data of Example 1 and Comparative Example 6, it can be seen that if the proportion of the oiliness agent in the formula composition is increased, both the low temperature performance and the anti-wear ability will be affected.

[0208] From the comparison of the data of Example 1 and Comparative Example 7, it can be seen that if the amount of the oiliness agent in the formula composition is reduced, both the low temperature performance and the anti-wear ability will be affected.

[0209] In addition, the present invention uses the MTM micro traction tester produced by PCS in the UK to test the traction coefficients of Example 1 and Comparative Examples 2, 4, 6 and 8, wherein the test principle diagram of the MTM micro traction tester is as shown in FIG. Figure 1 As shown in the figure, the specific process is: put the oil to be tested into a steel pan, control the temperature of the oil through a heating element, and let the steel ball roll in the oil. During the test, the traction coefficient under different slide-roll ratio conditions at a certain temperature (40°C) is determined by changing the computer program, and a traction coefficient-slide-roll ratio curve is formed.

[0210] Specific test results are as follows Figure 2 As shown by Figure 2It can be seen that Example 1 of the lubricating oil of the present invention has the lowest traction coefficient and can provide the best energy efficiency. Compared with Comparative Example 8, the traction coefficient of Example 1 decreases by more than 20%, which can provide an improvement of more than 20% in energy efficiency.

[0211] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0212] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A lubricating oil for a yaw and pitch reducer of a wind turbine generator set, characterized in that: The lubricating oil comprises, by weight: 49-53 parts of metallocene polyalphaolefin, 23-28 parts of functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, 15-20 parts of alkyl naphthalene, 2.5-3.0 parts of composite additive package, 2-5 parts of oiliness agent, 0.005-0.01 parts of demulsifier, 0.02-0.03 parts of defoamer, and 0.005-0.01 parts of pour point depressant; The weight ratio of the functional fluid containing the low-viscosity and low-volatility poly-alpha-olefin base material and the alkyl naphthalene is (1.15-1.80): 1; The weight ratio of the metallocene polyalphaolefin to the alkyl naphthalene is (2.4-3.0): 1; The mass ratio of the alkyl naphthalene to the oiliness agent is (3-10):1; The functional fluid containing a low-viscosity, low-volatility poly-alpha-olefin base material is oligomeric alpha-olefin MAX3.5; The oiliness agent is at least one of polyester and fatty acid ester; The metallocene polyalphaolefin is MPAO150; the alkyl naphthalene has a kinematic viscosity of 20-100 cst at 40° C.; the composite additive package is HITEC 307; and the pour point depressant is a polymethacrylate polymer.

2. The lubricating oil for the yaw and pitch reducer of a wind turbine generator set according to claim 1, characterized in that: The demulsifier is at least one of polyethylene glycol fatty acid ester and ethylene oxide-propylene oxide block copolymer; The defoaming agent is at least one of an organic silicon defoaming agent and a non-silicon defoaming agent.

3. A method for preparing lubricating oil for a yaw and pitch reducer of a wind turbine generator set according to any one of claims 1 to 2, characterized in that: The preparation method is: S1, adding metallocene polyalphaolefin, functional fluid containing low-viscosity and low-volatility polyalphaolefin base material, and alkyl naphthalene into a blending kettle, heating and stirring evenly; S2, adding composite additives, oiliness agent, pour point depressant, demulsifier and defoamer into the blending kettle in sequence and mixing evenly; S3. After the blending is completed, the lubricating oil is filtered using a filter bag with a filter diameter not greater than 15 μm to obtain the lubricating oil for the yaw and pitch control reducer of the wind turbine generator set.

Images