A pipe filter for the inlet of a working fluid pump of a generator set and a method for designing the same

Abstract

The application discloses a pipeline filter for the inlet of a working medium pump of a generator set, which comprises a seamless steel pipe, an upper connecting piece, a filter assembly and a lower connecting piece, the upper connecting piece and the lower connecting piece are used for fixing the filter assembly, the filter assembly comprises a flange-to-jack sealing piece and a filter screen, the flange-to-jack sealing piece is arranged between the upper connecting piece and the lower connecting piece, the filter screen is fixed to one end of the flange-to-jack sealing piece and is placed in the seamless steel pipe, a balance piece and an anti-impact piece are fixed to the other end of the filter screen, compared with the prior art, the pipeline filter has a filtering area which is multiple times of that of a conventional filter, effectively reduces filter blockage, organic working medium cannot be vaporized due to the filter blockage, working medium pump cannot be vaporized due to cavitation, and the pipeline filter greatly improves the operation reliability and stability of an ORC power generation system. The pipeline filter is vertically installed in the pipeline and does not interfere with the external ORC power generation system, impurities are filtered and accumulated at the bottom of the filter during equipment operation, and working medium cannot be vaporized due to filter screen blockage.

Description

Technical Field

[0001] This invention relates to the field of pipeline impurity filtration, specifically to a pipeline filter for the inlet of a working fluid pump in a generator set and its design method. Background Technology

[0002] The Organic Rankine Cycle (ORC) is a Rankine cycle that uses low-boiling-point organic matter as the working fluid. It mainly consists of four parts: an evaporator, an expander generator, a condenser, and a working fluid pump. In the evaporator, the organic working fluid absorbs heat from waste heat, generating steam with a certain pressure and temperature. This steam then enters the expander, expanding and doing work to drive the generator or other power machinery. The Organic Rankine Cycle is an important method for recovering energy from low-temperature heat sources. With the introduction of goals such as "carbon peaking" and "carbon neutrality," a huge market for waste heat recovery has emerged. As one of the four core components of the ORC power generation system, the working fluid pump directly affects the reliability and stability of the ORC power generation system.

[0003] ORC power generation systems primarily use centrifugal pumps as working fluid pumps. Due to the high cost of organic working fluids, leaks in ORC power generation systems can cause significant property damage. Therefore, leaks in the working fluid pumps are minimized, and strict requirements are placed on the pump's sealing and the cleanliness of the working fluid at the pump inlet. A filter is installed at the working fluid pump inlet, and the appropriate filter type and installation method are crucial to the pump's performance. Currently, most domestic manufacturers use general-purpose water pumps as their working fluid pumps, and the filters they use are commonly found in water systems, which cannot effectively guarantee safety and performance.

[0004] Currently, traditional conical filters have a low effective filtration area and are only suitable for filtering impurities in ordinary pipelines. They also have high resistance after operation. Organic working fluids usually have low boiling points, so they are very easy to vaporize at the inlet of the working fluid pump, which can cause cavitation. In addition, the bottom of the conical filter has a cone-shaped structure, which is easily damaged after being impacted by liquid for a long time. Debris entering the working fluid pump can cause damage to the working fluid pump. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a pipeline filter for the inlet of a working fluid pump in a generator set, which does not occupy additional external space and has a filtration area many times larger than that of conventional filters, as well as its design method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A pipeline filter for the inlet of a working fluid pump in a generator set includes a seamless steel pipe, an upper connector, a filter assembly, and a lower connector. The upper and lower connectors are used to fix the filter assembly. The filter assembly includes a flange clamp seal and a filter screen. The flange clamp seal is disposed between the upper and lower connectors. The filter screen is fixed to one end of the flange clamp seal and placed inside the seamless steel pipe. A balancing component and an anti-impact component are fixed to the other end of the filter screen.

[0008] As a further preferred embodiment of the present invention, the upper connector includes an upper flange and an upper flange gasket for sealing, and the lower connector includes a lower flange and a lower flange gasket for sealing, wherein the lower flange is installed at one end of the seamless steel pipe.

[0009] As a further preferred embodiment of the present invention, the filter assembly further includes an external frame for supporting the filter screen, which is welded to the flange clamp seal. The filter screen is welded to the inside of the external frame to prevent the filter screen from falling off under long-term impact and affecting the operation of other equipment in the pipeline.

[0010] As a further preferred embodiment of the present invention, the filter screen is configured as a funnel structure, with the large end connected to the flange clamp seal. The shock-resistant component is made of stainless steel and welded to the bottom of the external frame. The impurities accumulate along the filter screen to the shock-resistant component at the bottom of the filter screen. Adding the shock-resistant component can increase the strength of the bottom of the filter screen and prevent the bottom of the filter screen from breaking after impact, causing impurities to return to the pipe and lose the filtering effect.

[0011] As a further preferred embodiment of the present invention, the balancing component is configured as four stainless steel columns, which are evenly arranged on the outer ring of the impact-resistant component by welding. The gap between the balancing component and the seamless steel pipe wall is extremely small, which can stabilize the filter assembly and prevent the filter assembly from shaking inside the seamless steel pipe.

[0012] A design method for a pipeline filter at the inlet of a working fluid pump in a generator set includes the following specific steps: S1, the filter screen is set as a funnel structure, and the diameters of the large and small ends of the filter screen are determined; D 大 =d-(2~3)D 小 =1 / 3 D 大 Where d is the diameter of the seamless steel pipe, in mm; S2, the filter height h is calculated. V S3. By consulting and calculating, the required net positive suction head (NPSH) of the working fluid pump and the friction loss Δf of the fluid flowing in the pipeline are obtained. p The resistance loss Δf caused by fluid flowing through the filter v S4. Determine the filter height h V Does the required net positive suction head (NPSH) of the working fluid pump meet the requirements, and calculate the filter height h? V The range of values ​​for; S5, if the filter height h calculated in S2 VAt the filter height h of S4 V If the value is within the range of h, then the calculated height is the filter height h. V S6. If the filter height h calculated in S2 V The filter height h is not in S4 V If the value is within the range, then the filter height h will be... V The maximum value in the range is taken as the filter height h. V S7. Select the aperture size, which should be 20μm-30μm.

[0013] As a further preferred embodiment of the present invention, the specific steps of step S2 are as follows: S2.1, according to S... V =ε π(D 大 +D 小 )√[(D 大 -D 小 )²+h v ²] , of which S V Where ε is the flow area, and ε is the filter screen opening ratio, which is the ratio of the filter opening area to the total area; S2.2, Substitute the formula in S2.1 into S V / S p =n, where S p The cross-sectional area of ​​the seamless steel pipe is given; based on production tests, n = 3~5; the filter height h is calculated using S2.3. V .

[0014] As a further preferred embodiment of the present invention, in step S3, the friction loss Δf of the fluid flowing in the pipe is... p via Δf p =λ(l-h V )v 2 The value is calculated as / 2dg, where d is the diameter of the seamless steel pipe, l is the length of the seamless steel pipe, v is the fluid velocity, and λ is the friction coefficient.

[0015] As a further preferred embodiment of the present invention, the resistance loss Δf generated by the fluid flowing through the filter in step S3 v via Δf v =ω 2 (1-ε 2 ) / 2gρ(CεSy) 2 Where ω is the fluid mass flow rate (kg / s); ε is taken as 0.11; and g is taken as 9.8 m / s. 2 ρ is the fluid density (kg / m³) 3 C is the dimensionless micropore coefficient, taken as 0.96; S is the total area of ​​the filter, S=π(D 大 +D 小 )√[(D大 -D 小 )²+h v ²]; y is the expansion factor, which is 0.92.

[0016] As a further preferred embodiment of the present invention, in step S4, according to P c +ρg(lh) V )-Δf p -Δf v ≥NPSH, the filter height h is calculated. V The range of values ​​for P, where P c Let ρ be the pressure of the fluid at the filter inlet, ρ be the fluid density, and g be the acceleration due to gravity, taken as 9.8 m / s². 2 h V denoted as 'filter height', and 'l' as 'length of seamless steel pipe'.

[0017] The advantages of this invention are: the pipeline filter of this invention does not occupy additional external space, and its filtration area is many times larger than that of conventional filters, effectively reducing filter clogging. Organic working fluids will not vaporize, and the working fluid pump will not experience cavitation, thereby greatly improving the reliability and stability of the ORC power generation system. The pipeline filter is installed vertically inside the pipeline, and it will not interfere with the external equipment of the ORC power generation system. During operation, impurities will be filtered and accumulated at the bottom of the filter, preventing vaporization of the working fluid and cavitation due to filter clogging. By adding anti-impact and balancing components, the filter assembly can be effectively stabilized, reducing filter screen sway, effectively protecting the filter screen, and extending the service life of the filter assembly. This invention is also applicable to the fields of low-temperature waste heat recovery and recycling power generation technology and LNG cold energy recovery power generation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the connection structure of the present invention;

[0019] Figure 2 This is a partial schematic diagram of the filter component;

[0020] Figure 3 This is a schematic diagram of the filter component.

[0021] The meanings of the reference numerals in the figure are as follows: 101, upper flange; 102, upper flange gasket; 103, filter assembly; 104, lower flange gasket; 105, lower flange; 106, seamless steel pipe; 201, flange clamp seal; 202, external frame; 203, filter screen; 204, shock absorber; 205, balancing component. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] Example 1:

[0024] Combination Figure 1-3 A pipeline filter for the inlet of a working fluid pump in a generator set, comprising a seamless steel pipe 106, characterized in that it includes an upper connector, a filter assembly 103, and a lower connector, the upper and lower connectors being used to fix the filter assembly 103.

[0025] The upper connector includes an upper flange 101 and an upper flange gasket 102 for sealing, and the lower connector includes a lower flange 105 and a lower flange gasket 104 for sealing. The lower flange 105 is installed at one end of the seamless steel pipe 106.

[0026] The filter assembly 103 includes a flange clamp seal 201, an outer frame 202 for supporting the filter screen 203, and the filter screen 203. The flange clamp seal 201 is disposed between the upper connector and the lower connector.

[0027] The outer frame 202 is welded to the flange clamp seal 201, and the filter screen 203 is welded to the inside of the outer frame 202 to prevent the filter screen 203 from falling off under long-term impact and affecting the operation of other equipment in the pipeline.

[0028] The filter screen 203 is fixed to one end of the flange clamp seal 201 and placed inside the seamless steel pipe 106. The other end of the filter screen 203 is fixed with a balance member 205 and an anti-impact member 204.

[0029] The filter screen 203 is designed as a funnel structure, with its large end connected to the flange clamp seal 201. The shock absorber 204 is made of stainless steel and welded to the bottom of the outer frame 202. The impurities accumulate along the filter screen 203 to the shock absorber 204 at the bottom of the filter screen 203. Adding the shock absorber 204 can increase the strength of the bottom of the filter screen 203 and prevent the bottom of the filter screen 203 from breaking after impact, causing impurities to return to the pipe and lose the filtering effect.

[0030] The balance component 205 is composed of four stainless steel columns, which are evenly welded to the outer ring of the shock-resistant component 204. The gap between the balance component 205 and the wall of the seamless steel pipe 106 is extremely small, which can stabilize the filter assembly 103 and prevent the filter assembly 103 from shaking inside the seamless steel pipe 106.

[0031] The filter assembly 103 is installed inside the pipeline and fixed by the flange clamp seal 201. The organic working fluid enters the filter assembly 103 from the top of the pipeline. After passing through the internal filter screen 203 of the pipeline filter, the working fluid enters the working fluid pump. Impurities cannot pass through the internal filter screen 203 of the pipeline filter. The impurities eventually accumulate along the internal filter screen 203 of the filter assembly 103 to the anti-impact component 204 at the bottom of the filter assembly 103. The filter assembly 103 is installed inside the pipeline and will not interfere with the external environment of the ORC power generation system. It can also ensure that it has a filtration area many times larger than that of ordinary filters, which can effectively reduce filter clogging. The organic working fluid will not vaporize as a result, and the working fluid pump will not experience cavitation, thereby greatly improving the operational reliability and stability of the ORC power generation system.

[0032] Example 2:

[0033] A design method for a pipeline filter at the inlet of a working fluid pump in a generator set includes the following specific steps:

[0034] S1. The filter screen is designed as a funnel structure; determine the diameters of the large and small ends of the filter screen. D 大 =d-(2~3)D 小 =1 / 3 D 大 , where d is the diameter of the seamless steel pipe, in mm.

[0035] S2. Calculate the filter height h. V .

[0036] The specific steps of step S2 are as follows:

[0037] S2.1, according to S V =ε π(D 大 +D 小 )√[(D 大 -D 小 )²+h v ²] , of which S V ε represents the flow area, and ε is the filter screen opening ratio, which is the ratio of the filter opening area to the total area.

[0038] S2.2, Substitute the formula in S2.1 into S... V / S p =n, where S p The cross-sectional area of ​​the seamless steel pipe is given; based on production tests, n = 3~5.

[0039] S2.3 calculates the filter height h V .

[0040] S3. By consulting and calculating, the required net positive suction head (NPSH) of the working fluid pump and the friction loss Δf of the fluid flowing in the pipeline are obtained. p The resistance loss Δf caused by fluid flowing through the filter v .

[0041] Friction loss Δf of fluid flowing in a pipe p via Δf p =λ(l-h V )v 2 The value is calculated as / 2dg, where d is the diameter of the seamless steel pipe, l is the length of the seamless steel pipe, v is the fluid velocity, and λ is the friction coefficient.

[0042] The resistance loss Δf caused by fluid flowing through the filter v Through Δf v =ω 2 (1-ε 2 ) / 2gρ(CεSy) 2 Where ω is the fluid mass flow rate (kg / s); ε is taken as 0.11; and g is taken as 9.8 m / s. 2 ρ is the fluid density (kg / m³) 3 C is the dimensionless micropore coefficient, taken as 0.96; S is the total area of ​​the filter, S=π(D 大 +D 小 )√[(D 大 -D 小 )²+h v ²] ; y is the expansion factor, which is 0.92.

[0043] S4. Determine the filter height h V Does the required net positive suction head (NPSH) of the working fluid pump meet the requirements, and calculate the filter height h? V The range of values ​​for .

[0044] According to P c +ρg(lh) V )-Δf p -Δf v ≥ NPSH, calculate the filter height h V The range of values ​​for P, where P c Let ρ be the pressure of the fluid at the filter inlet, ρ be the fluid density, and g be the acceleration due to gravity, taken as 9.8 m / s². 2 h V denoted as 'filter height', and 'l' as 'length of seamless steel pipe'.

[0045] S5. If the filter height h calculated in S2 is... V At the filter height h of S4 V If the value is within the range of h, then the calculated height is the filter height h. V .

[0046] S6. If the filter height h calculated in S2 is... V The filter height h is not in S4 V If the value is within the range, then the filter height h will be... V The maximum value in the range is taken as the filter height h. V .

[0047] S7. Select the aperture size, which should be 20μm-30μm.

[0048] The advantages of this invention are: the pipeline filter of this invention does not occupy additional external space, and its filtration area is many times larger than that of conventional filters, effectively reducing filter clogging. Organic working fluids will not vaporize, and the working fluid pump will not experience cavitation, thereby greatly improving the reliability and stability of the ORC power generation system. The pipeline filter is installed vertically inside the pipeline, and it will not interfere with the external equipment of the ORC power generation system. During operation, impurities will be filtered and accumulated at the bottom of the filter, preventing vaporization of the working fluid and cavitation caused by clogging the filter screen 203. By adding anti-impact components 204 and balancing components 205, the filter assembly 103 can be effectively stabilized, reducing filter screen 203 shaking, effectively protecting the filter screen 203, and extending the service life of the filter assembly 103.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A pipeline filter for the inlet of a working fluid pump in a generator set, comprising a seamless steel pipe, characterized in that, The filter assembly includes an upper connector, a filter component, and a lower connector. The upper and lower connectors are used to fix the filter component. The filter component includes a flange clamp seal and a filter screen. The flange clamp seal is disposed between the upper and lower connectors. The filter screen is fixed to one end of the flange clamp seal and placed inside a seamless steel pipe. A balancer and an anti-impact component are fixed to the other end of the filter screen. The filter assembly also includes an external frame for supporting the filter screen, which is welded to the flange clamp seal. The filter screen is welded to the inner side of the external frame. The anti-impact component is made of stainless steel and is welded to the bottom of the external frame. The balancer consists of four stainless steel columns, which are evenly distributed around the outer ring of the anti-impact component by welding.

2. A pipeline filter for the inlet of a working fluid pump in a generator set according to claim 1, characterized in that, The upper connector includes an upper flange and an upper flange gasket for sealing, and the lower connector includes a lower flange and a lower flange gasket for sealing, wherein the lower flange is installed at one end of the seamless steel pipe.

3. A design method for a pipeline filter for the inlet of a working fluid pump in a generator set, as described in any one of claims 1-2, characterized in that, The specific steps include: S1, setting the filter screen to a funnel structure, and determining the diameters of the large and small ends of the filter screen; D 大 =d-(2~3)D 小 =1 / 3 D 大 Where d is the diameter of the seamless steel pipe, in mm; S2, the filter height h is calculated. V S3. By consulting and calculating, the required net positive suction head (NPSH) of the working fluid pump and the friction loss Δf of the fluid flowing in the pipeline are obtained. p The resistance loss Δf caused by fluid flowing through the filter v S4. Determine the filter height h V Does the required net positive suction head (NPSH) of the working fluid pump meet the requirements, and calculate the filter height h? V The range of values ​​for; S5, if the filter height h calculated in S2 V At the filter height h of S4 V If the value is within the range of h, then the calculated height is the filter height h. V S6. If the filter height h calculated in S2 V The filter height h is not in S4 V If the value is within the range, then the filter height h will be... V The maximum value in the range is taken as the filter height h. V S7. Select the aperture size, which should be 20μm-30μm.

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