Vacuum coalescence combined oil filtering system

Abstract

A vacuum coalescence combined oil filtering system relates to the technical field of lubricating oil purification, and adopts the technical scheme that the vacuum coalescence combined oil filtering system comprises a skid-mounted frame, and the skid-mounted frame is provided with a coalescence dehydration unit and a vacuum dehydration unit; the coalescence dehydration unit comprises an oil inlet pump, a pre-filtering impurity filter and a coalescence separator which are connected in sequence; the vacuum dehydration unit comprises a heater and a vacuum separator which are sequentially connected, an oil inlet of the heater is connected with an oil outlet of the coalescence separator, an exhaust port of the vacuum separator is sequentially connected with a condenser and a vacuum pump, and an oil discharge port of the vacuum separator is sequentially connected with an oil outlet pump and a filtered impurity filter. Various dewatering and filtering devices are integrated into a skid-mounted structure, the occupied space is small, flexible selection of various filtering modes is achieved, and the treatment efficiency of lubricating oil is improved; and rising airflow is added to the vacuum separator to assist in dehydration, so that the requirements of the vacuum separator on the vacuum degree and the heating temperature are reduced, and the energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oil purification, and particularly to a vacuum coalescence combined oil filtering system. Background Art

[0002] The lubricating oil of a steam turbine is the working medium of the lubrication and speed regulation system of a steam turbine generator set in a thermal power plant. During the use of the lubricating oil, the gradual deterioration of the anti-emulsification performance is inevitable. Generally, there are three reasons: moisture, emulsifier, and high-speed stirring. Among them, moisture is the main cause of oil emulsification. During the operation of the steam turbine, many factors such as loose shaft seals of the unit, steam leakage of the steam seal, the oil being under thermal load, open oil storage, and the vacuum degree of the bearing box and oil tank not reaching the required level will cause moisture to mix into the lubricating oil, resulting in oil emulsification. Moisture exists in the oil in two forms: dissolved water and free water. In existing oil-water separation equipment, the coalescence separator has a fast dehydration speed and a high processing capacity, but it is difficult to remove dissolved water; the vacuum separator can remove free water and dissolved water, and has a higher dehydration rate, but has a low dehydration efficiency and high energy consumption; if impurities in the oil also need to be removed, an impurity filtering oil purifier needs to be added; during use, there are also problems such as unreasonable configuration of multiple devices, large floor space, cumbersome operation, and low filtering efficiency. Summary of the Invention

[0003] In view of the problems that each of the oil-water separation devices in the prior art solutions has its own disadvantages and the configuration of multiple devices is unreasonable, the present invention provides a vacuum coalescence combined oil filtering system.

[0004] The present invention provides the following technical solution: A vacuum coalescence combined oil filtering system, comprising: A skid-mounted frame, which is provided with a coalescence dehydration unit and a vacuum dehydration unit; The coalescence dehydration unit includes an inlet oil pump, a pre-filter impurity filter, and a coalescence separator connected in sequence; The vacuum dehydration unit includes a heater and a vacuum separator connected in sequence. The inlet oil port of the heater is connected to the outlet oil port of the coalescence separator. The exhaust port of the vacuum separator is connected to a condenser and a vacuum pump in sequence. The outlet oil port of the vacuum separator is connected to an outlet oil pump and a post-filter impurity filter in sequence.

[0005] Preferably, it further includes a first three-way valve and a second three-way valve. The first interface of the first three-way valve is connected to the pre-filter impurity filter, the second interface of the first three-way valve is connected to the coalescence separator, the outlet oil port of the coalescence separator and the third interface of the first three-way valve are both connected to the first interface of the second three-way valve. The second interface of the second three-way valve is connected to the heater, and the third interface of the second three-way valve and the outlet oil port of the outlet oil pump are both connected to the post-filter impurity filter.

[0006] Preferably, check valves are provided at the oil outlet of the coalescing separator and the oil outlet of the oil pump.

[0007] Preferably, a coarse filter is also provided at the oil suction port of the inlet oil pump.

[0008] Preferably, a water collecting tank is provided at the bottom of the coalescing separator, and a liquid level gauge and a drain valve are provided on the water collecting tank. The drain valve is sequentially connected to a water filter and a drain solenoid valve.

[0009] Preferably, a water receiving tray is provided at the bottom of the skid-mounted frame, and a drain valve and a float switch are provided on the water receiving tray.

[0010] Preferably, the vacuum separator includes a tank body and an atomizer provided in the tank body. An oil inlet connected to the atomizer and an exhaust port connected to the condenser are provided at the top of the tank body, and an oil drain port connected to the outlet oil pump is provided at the bottom of the tank body.

[0011] Preferably, an air inlet is further provided on the tank body. The air inlet is located at the bottom of the atomizer, and the air inlet is connected to an air filter.

[0012] Preferably, the heater heats the lubricating oil to 40 - 50 °C, and the vacuum degree in the vacuum separator is at least 60 kPa.

[0013] The beneficial effects of the present invention are as follows: A variety of dehydration and filtration devices are integrated into a skid-mounted structure, with a compact equipment layout and a small occupied space. Optimized pipelines are used to connect various devices to achieve flexible selection of various filtration modes, improving the processing efficiency of lubricating oil; The vacuum separator increases the upward air flow to assist in dehydration, reducing the requirements for the vacuum degree and heating temperature of the vacuum separator, reducing energy consumption, and having less impact on the physical and chemical properties of lubricating oil, thus extending the service life of lubricating oil. Description of the Drawings

[0014] Figure 1 It is a front view of an embodiment of the present invention.

[0015] Figure 2 It is a rear view of an embodiment of the present invention.

[0016] Figure 3 It is a device connection diagram of an embodiment of the present invention.

[0017] Figure 4 It is a schematic diagram of the vacuum separator of an embodiment of the present invention.

[0018] Reference Numerals: 10, skid-mounted frame; 20, inlet oil pump; 21, coarse filter; 30, pre-filter impurity filter; 31, first three-way valve; 32, second three-way valve; 40, coalescing separator; 41, water collection tank; 42, water filter; 50, heater; 60, vacuum separator; 61, condenser; 62, vacuum pump; 63, atomizer; 70, outlet oil pump; 80, post-filter impurity filter. Detailed Embodiment

[0019] The following further elaborates on the embodiments of the present invention in conjunction with the attached drawings and reference numerals, enabling those skilled in the art to implement it after studying this specification. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Embodiment 1

[0021] The present invention provides a Figures 1-3 shown vacuum coalescence combined oil filtering system, including a skid-mounted frame 10 and a coalescence dehydration unit and a vacuum dehydration unit arranged on the skid-mounted frame 10, integrating multiple devices for treating dissolved water, free water, and impurities into an orderly skid-mounted structure, reducing the occupied space, and connecting multiple devices with optimized pipelines to achieve flexible selection of multiple filtering modes and improve the treatment efficiency of lubricating oil.

[0022] The coalescence dehydration unit includes an inlet oil pump 20, a pre-filter impurity filter 30, and a coalescing separator 40 connected in sequence, mainly for treating free water in lubricating oil. The oil suction port of the inlet oil pump 20 is connected to the oil transmission pipeline, pressurizing and pumping the lubricating oil liquid in the oil transmission pipeline into the coalescence dehydration unit. Its oil suction port is also connected to a coarse filter 21, which can adopt a Y-type filter, small in volume and convenient to install, for filtering large particle impurities in the oil liquid to protect the inlet oil pump 20. The pre-filter impurity filter 30 can adopt an oil suction filter with a filtration accuracy of 185 μm to further filter impurities in the oil liquid. The coalescing separator 40 can refer to related technologies, and its coalescence separation chamber contains coalescence filter elements and separation filter elements. After the lubricating oil liquid flows into the coalescence separation chamber from the inlet N1 of the coalescing separator, it first flows through the lower coalescence filter element, and the fine free water in the oil liquid forms larger water droplets through polymerization. Then, when the oil liquid enters the separation filter element, due to the blocking effect of the separation filter element on the water droplets and the fact that the specific gravity of the water droplets is greater than that of the oil, the water droplets sink downward into the water collection tank 41 below the coalescence separation chamber, and the oil liquid is discharged from the oil outlet N2. The water collection tank 41 is provided with a liquid level gauge and a drain valve, and the drain valve is sequentially connected to a water filter 42 and a drain solenoid valve. When the liquid level in the water collection tank 41 rises to a specified height, the drain solenoid valve is opened for drainage.

[0023] The vacuum dehydration unit is used to further remove the dissolved water and dissolved gas in the lubricating oil, and includes a heater 50 and a vacuum separator 60 connected in sequence. The oil inlet of the heater 50 is connected to the oil outlet N2 of the coalescing separator 40. The exhaust port N4 of the vacuum separator 60 is sequentially connected to a condenser 61 and a vacuum pump 62. The oil discharge port N5 of the vacuum separator 60 is sequentially connected to an oil pump 70 and a post-filter impurity filter 80.

[0024] The lubricating oil liquid treated by the coalescing dehydration unit is heated to a preset temperature range by the heater 50 and then enters the vacuum separator 60. The heater 50 provides the temperature required for oil-water separation. The heater 50 can adopt PID temperature control technology. When the temperature of the lubricating oil liquid at the oil inlet of the heater 50 is less than the preset temperature range and the oil level in the vacuum separator 60 reaches the lower limit, the heater 50 starts to heat the lubricating oil liquid. When the oil temperature exceeds the preset temperature range, the heater 50 stops working. The vacuum pump 62 provides the vacuum degree required for oil-water separation inside the vacuum separator 60. The vacuum separator 60 includes a tank body and an atomizer 63 arranged inside the tank body. An oil inlet N3 connected to the atomizer 63 and an exhaust port N4 connected to the condenser 61 are arranged at the top of the tank body. An oil discharge port N5 connected to the oil pump 70 is arranged at the bottom of the tank body. The lubricating oil liquid is atomized by the atomizer 63 and then falls. At the same temperature, there is a large difference in the saturated vapor pressures of oil and water. Under the high vacuum state, water vaporizes before oil, so that oil and water are separated. The oil droplets continue to fall to the bottom of the tank body. A liquid level gauge is arranged at the bottom of the tank body. After the oil liquid accumulates to a preset height, it is pumped out by the oil pump 70. The water vapor flows out of the exhaust port N4 to the condenser 61 and condenses into a liquid under the negative pressure formed by the vacuum pump 62, and the gas phase is discharged by the vacuum pump 62. The post-filter impurity filter 80 is a fine filter with a filtration accuracy of 3μm to filter out the mechanical particles in the lubricating oil liquid.

[0025] Further, the oil filtering system further includes a first three-way valve 31 and a second three-way valve 32. By different connection modes of the two three-way valves, three filtering modes are realized. Specifically, the first interface of the first three-way valve 31 is connected to the pre-filter impurity filter, the second interface of the first three-way valve 31 is connected to the inlet N1 of the coalescing separator, the third interface of the first three-way valve 31 and the oil outlet N2 of the coalescing separator 40 are both connected to the first interface of the second three-way valve 32. The second interface of the second three-way valve 32 is connected to the heater, and the third interface of the second three-way valve 32 and the oil outlet of the oil pump 70 are both connected to the post-filter impurity filter 80. Check valves are arranged at the oil outlets of the coalescing separator 40 and the oil pump 70 to prevent the oil liquid from flowing back.

[0026] The three filtering modes are as follows: First, connect the first interface and the second interface of the first three-way valve 31, and connect the first interface and the third interface of the second three-way valve 32, so as to complete coalescence dehydration and impurity removal; Second, connect the first interface and the third interface of the first three-way valve 31, and connect the first interface and the second interface of the second three-way valve 32, so as to complete vacuum dehydration and impurity removal; Third, connect the first interface and the second interface of the first three-way valve 31, and connect the first interface and the second interface of the second three-way valve 32, so as to complete coalescence dehydration, vacuum dehydration and impurity removal. First, most of the free water is removed by coalescence dehydration, and then the dissolved water is removed by vacuum dehydration, further reducing the water content. At the same time, the amount of water to be removed by the vacuum separator is reduced, the energy consumption is reduced, and the dehydration efficiency is enhanced. According to the composition and water content requirements of free water and dissolved water in the lubricating oil, the filtering mode can be flexibly selected.

[0027] Preferably, a water receiving tray is arranged at the bottom of the skid-mounted frame 10 to prevent water from flowing out and polluting the environment. The water receiving tray is provided with a drain valve and a float switch. When the water level in the water receiving tray rises to a preset liquid level, the float switch feeds back a signal to the controller, and the controller opens the drain valve to drain water.

[0028] Embodiment 2

[0029] The present invention provides a vacuum coalescence combined oil filtering system. On the basis of Embodiment 1, the tank body is further provided with an air inlet N6. The air inlet N6 is located at the bottom of the atomizer 63. The air inlet N6 is connected with an air filter. Please refer to Figure 4 。

[0030] The air filter filters out the moisture in the air. The dry air enters from the air inlet N6 below the atomizer 63, and forms an upward air flow under the negative pressure of the vacuum pump. It travels in the opposite direction to the falling oil mist droplets, takes away the moisture in the atomized droplets, and improves the dehydration effect. When the upward air flow is not increased in the tank body, the vacuum separator needs a relatively high vacuum degree and temperature for oil-water separation. Its vacuum degree needs to reach at least 90 kPa, and the heater needs to heat the lubricating oil temperature to at least 60 °C to obtain a greater difference in saturated vapor pressure for easy dehydration; after increasing the upward air flow, the temperature of the lubricating oil entering the vacuum separator can be reduced to 40-50 °C, and the minimum vacuum degree requirement can be reduced to 60 kPa, so that 100% of the free water, 95% of the dissolved water and 90% of the dissolved gas in the lubricating oil can be removed, and the water content of the lubricating oil can be less than 50 PPm, greatly reducing the energy consumption. At the same time, the physical and chemical properties of the lubricating oil are less affected, and the service life of the lubricating oil is extended.

[0031] The turbine lubricating oil to be filtered is evenly divided into three parts, which are processed by two groups of Example 1 and one group of Example 2 respectively. The coalescence dehydration and vacuum dehydration combined filtration mode is adopted. Except for the different operating conditions of the vacuum separator, other test conditions are the same. Finally, the water content of the processed lubricating oil is detected by a micro water tester. Multiple tests are carried out to obtain the average water content, and the results are shown in Table 1.

[0032] Table 1: Comparison table of different operating conditions of the vacuum separator

[0033] As can be seen from Table 1, due to the decrease in the vacuum degree and the temperature of the lubricating oil after heating by the heater, compared with the first group, the average water content of the second group increases significantly, indicating that reducing the operating conditions of the vacuum separator in Example 1 has a greater impact on its filtration effect; the difference in the average water content between the third group and the first group is not large, indicating that increasing the upward air flow in the vacuum separator helps to improve the filtration effect, and the requirements for the operating conditions of the vacuum separator decrease, reducing the energy consumption.

[0034] The above are one or more embodiments of the present invention, and the description is relatively specific and detailed, but it should not be understood as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A vacuum coalescence combined oil filtration system, characterized in that: include: A skid-mounted frame, wherein the skid-mounted frame is provided with a coalescing and dehydrating unit and a vacuum dehydrating unit; The coalescence and dehydration unit comprises an oil feed pump, a pre-filter impurity filter and a coalescence separator connected in sequence; The vacuum dehydration unit comprises a heater and a vacuum separator which are connected in sequence, wherein the oil inlet of the heater is connected to the oil outlet of the coalescing separator, the exhaust port of the vacuum separator is connected to a condenser and a vacuum pump in sequence, and the oil discharge port of the vacuum separator is connected to an oil outlet pump and a post-filtration impurity filter in sequence.

2. A vacuum coalescence combined oil filtration system according to claim 1, characterized in that: It also includes a first three-way valve and a second three-way valve, wherein the first interface of the first three-way valve is connected to the pre-filtration impurity filter, the second interface of the first three-way valve is connected to the coalescing separator, the oil outlet of the coalescing separator and the third interface of the first three-way valve are both connected to the first interface of the second three-way valve, the second interface of the second three-way valve is connected to the heater, and the third interface of the second three-way valve and the oil outlet of the oil pump are both connected to the post-filtration impurity filter.

3. A vacuum coalescence combined oil filtration system according to claim 2, characterized in that: The oil outlet of the coalescing separator and the oil outlet of the oil outlet pump are both provided with a one-way valve.

4. The vacuum coalescence combined oil filtration system according to claim 1, characterized in that: The oil suction port of the oil feed pump is also provided with a coarse filter.

5. The vacuum coalescence combined oil filtration system according to claim 1, characterized in that: A water collecting tank is arranged at the bottom of the coalescing separator, and the water collecting tank is provided with a liquid level meter and a drain valve, and the drain valve is connected with a water filter and a drain solenoid valve in sequence.

6. A vacuum coalescence combined oil filtration system according to claim 5, characterized in that: A water receiving tray is arranged at the bottom of the skid-mounted frame, and the water receiving tray is provided with a drain valve and a float switch.

7. The vacuum coalescence combined oil filtration system according to claim 1, characterized in that: The vacuum separator comprises a tank body and an atomizer arranged in the tank body. The top of the tank body is provided with an oil inlet connected to the atomizer and an exhaust port connected to the condenser. The bottom of the tank body is provided with an oil discharge port connected to the oil outlet pump.

8. A vacuum coalescence combined oil filtration system according to claim 7, characterized in that: The tank body is also provided with an air inlet, which is located at the bottom of the atomizer and is connected to an air filter.

9. A vacuum coalescence combined oil filtration system according to claim 8, characterized in that: The heater heats the lubricating oil to 40-50° C., and the vacuum degree in the vacuum separator is at least 60 kPa.

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