Geothermal power station steam discharge silencer and design method thereof

Abstract

The invention discloses a geothermal power station steam discharge silencer and a design method thereof. The silencer comprises at least one silencing pit, a silencer body and a silencer cover, steam discharge holes are formed in the wall of the diffuser, the diffuser is arranged in the middle of the silencing pit, and an inlet of the diffuser is connected to a steam discharge port of the geothermal power station; a silencing material with pores is filled between the diffuser and the inner wall of the silencing pit; and by adjusting the discharge flow of the steam, it is ensured that the steam is in a laminar flow state in the silencing pit. The silencer is arranged, the structure of the silencer converts steam energy into heat energy and sound energy through multiple reflection, scattering and friction modes, the absorption and attenuation capacity on low-frequency noise is enhanced, the silencing effect is improved, the silencing pit of the silencer is designed to be modularized and extensible, installation, maintenance and expansion are convenient, and the silencer is convenient to use. The operation flexibility of the silencer is improved, the silencer is high in thermal stress adaptability and rapid to start and stop, and safe and stable operation of the geothermal power station under various working conditions can be achieved.

Description

Technical Field

[0001] The present invention belongs to the field of geothermal power generation steam emission noise reduction, and in particular, relates to a geothermal power station steam emission silencing device and a design method thereof. Background Art

[0002] Geothermal power generation technology relies on flash steam generated at the geothermal wellhead to drive turbines for power production, a process that demonstrates its significant advantages in environmental protection and sustainability. However, under certain operating conditions such as the unit startup phase, performance testing or load mutation (such as load shedding), the wellhead steam needs to be released directly into the atmosphere. This operation places strict requirements on the reliability of the steam exhaust silencer, because the stable operation of the device is directly related to the safety of the geothermal generator unit under various operating conditions and the overall performance of the entire power plant. It is worth noting that the strong noise accompanying the wellhead steam discharge process poses a threat to the surrounding ecological environment that cannot be ignored. To make it more complicated, geothermal steam often contains high concentrations of corrosive media, multiple minerals and other components, and the equipment pipelines are prone to scaling, which increases the difficulty of noise control. Traditional microporous silencers and sound isolators are widely used in the field of conventional noise control, but in the face of geothermal steam emissions, strong corrosiveness and easy scaling environments, these traditional methods cannot guarantee long-term, safe and effective operation.

[0003] Therefore, in view of the unique steam emission and noise control challenges in the field of geothermal power generation, it is necessary to develop or adopt a silencer with stronger environmental adaptability. In view of this, the present invention is specially proposed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a geothermal power plant steam exhaust silencing device and a design method thereof.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] In a first aspect, the present invention provides a geothermal power plant steam exhaust silencing device, comprising:

[0007] at least one silencing pit;

[0008] A diffuser, the wall of which is provided with a steam discharge hole, is arranged in the middle of the muffler pit, and the inlet of the diffuser is connected to the steam discharge port of the geothermal power station;

[0009] A sound-absorbing material having pores is filled between the diffuser and the inner wall of the sound-absorbing pit;

[0010] By adjusting the steam discharge flow rate, ensure that it is in a laminar flow state inside the silencer pit.

[0011] In a preferred embodiment, a protective cover is provided between the diffuser and the sound-absorbing material.

[0012] In a preferred embodiment, an opening is provided at the bottom of the protective cover, and the steam discharge hole is arranged at the lower half of the diffuser.

[0013] In a preferred embodiment, a drainage outlet is provided at the lower portion of the side wall and / or the bottom wall of each silencing pit.

[0014] In a preferred embodiment, the sound-absorbing material is porous volcanic rock.

[0015] In a preferred embodiment, the density of the porous volcanic rock is less than 2600 kg / m 3 , porosity is greater than or equal to 0.25, and particle diameter is 50 to 300 mm.

[0016] In a second aspect, the present invention also provides a design method for a steam exhaust silencing device of a geothermal power plant, the method comprising: calculating the minimum superficial fluidization velocity according to the following equation, and verifying that the steam flow rate should be less than the minimum superficial fluidization velocity,

[0017]

[0018] in,

[0019] d p ——Diameter of the sound-absorbing material particles, in m;

[0020] ρ g ——Steam density, in kg / m 3 ;

[0021] ρ p ——Density of sound-absorbing material, in kg / m 3 ;

[0022] g——acceleration due to gravity, about 9.81m / s;

[0023] μ g ——dynamic viscosity of steam, in Pa·s or kg / (m·s);

[0024] ε——porosity of sound-absorbing material;

[0025] L——total length of silencer, in meters;

[0026] ——The pressure drop of steam flowing through the silencer, in Pa;

[0027] U mf ——minimum superficial fluidization velocity, in m / s;

[0028] By adjusting key parameters such as the particle diameter, porosity, and size of the silencer, cyclic iterative calculations are performed, and the appropriate particle diameter, porosity, and size of the silencer are further adjusted and selected based on the calculation results to achieve the best performance.

[0029] In a preferred embodiment, in the equation:

[0030]

[0031] In a preferred embodiment, the design method further includes: obtaining the Reynolds number of the silencer material by calculating the flow state of the steam fluid in the silencer pit to determine whether the steam fluid flow is in a laminar flow, transitional flow or turbulent flow state. The calculation formula of the Reynolds number of the silencer material is as follows:

[0032]

[0033] in,

[0034] ρ g ——Steam density, in kg / m 3

[0035] u g ——The flow velocity of steam in the muffler pit, in m / s;

[0036] d p ——Diameter of the sound-absorbing material particles, in m;

[0037] μ g ——Dynamic viscosity of steam, unit is Pa·s or kg / (m·s).

[0038] In a preferred embodiment, the flow velocity of geothermal steam in each section of the muffler is calculated by a formula, which is as follows:

[0039]

[0040] in,

[0041] ——Steam flow rate in the silencing pit, in kg / s;

[0042] υ su ——The speed of the steam flowing upward in the muffler pit, in m / s;

[0043] A pit ——Cross-sectional area of ​​the silencing pit, in m 2 ;

[0044]

[0045] in,

[0046] υ sd ——The speed at which steam flows downward through the diffuser, in m / s;

[0047] A db ——Diffuser cross-sectional area, in m 2 ;

[0048]

[0049] in,

[0050] ν sh ——The horizontal flow velocity of steam from the diffuser to the wall of the muffler pit, in m / s;

[0051] A rp ——The cross-sectional area of ​​the steam flow from the diffuser to the wall of the muffler pit, in m 2 .

[0052] After adopting the above technical solution, the geothermal power station steam exhaust silencing device and its design method provided by the present invention have the following beneficial effects compared with the prior art:

[0053] (1) The present invention is provided with a silencer, the structure of which converts steam energy into heat energy and sound energy dissipation through multiple reflections, scattering and friction, thereby enhancing the absorption and attenuation capabilities of low-frequency noise and improving the silencer effect. The silencer pit of the silencer is designed to be modular and expandable, which is convenient for installation, maintenance and expansion, and improves the flexibility of the operation of the silencer. The silencer has strong adaptability to thermal stress and rapid start and stop, and can achieve safe and stable operation under various working conditions of the geothermal power station.

[0054] (2) The present invention uses porous volcanic rock as the silencer material, utilizing the rock's chemical corrosion resistance to reduce the damage to the silencer caused by minerals and corrosive media in the steam.

[0055] (3) The present invention enhances the structural stability and performance of the silencer by optimizing the structural design and the pores and arrangement of the silencer.

[0056] (4) The design and calculation method of the rock silencer provided by the present invention has strong dynamic adaptability, improved silencer efficiency, and high noise reduction stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the accompanying drawings:

[0058] Figure 1 is a transverse cross-sectional view of the steam exhaust silencing device of a geothermal power station of the present invention;

[0059] Figure 2 It is a longitudinal cross-sectional view of the steam exhaust silencing device of a geothermal power station according to the present invention.

[0060] In the figure:

[0061] 1. Silence pit;

[0062] 2. Diffuser;

[0063] 21. Steam discharge hole;

[0064] 3. Sound-absorbing materials;

[0065] 4. Support frame;

[0066] 5. Protective cover.

[0067] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0068] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0069] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0070] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0072] Example 1

[0073] The present embodiment provides a geothermal power station steam exhaust silencer, including at least one silencer pit 1. The silencer pit 1 is in the shape of a rectangular parallelepiped with an open top as a whole, and can be made of concrete or other materials. A diffuser 2 is provided in the silencer pit 1. The diffuser 2 is tubular and is arranged in the middle of the silencer pit 1. It is preferably made of metal, such as steel. The tubular diffuser 2 extends into the silencer pit 1 through a side wall of the silencer pit 1. Its inlet is connected to the steam exhaust port of the external geothermal power station by a flange, which is convenient for disassembly and maintenance. A steam exhaust hole 21 is provided on its wall. Along the direction in which the diffuser 2 extends, a plurality of support frames 4 are arranged below the diffuser 2 to provide support force. The support frames 4 can be made of metal or other heat-resistant materials, or can be made of concrete to reduce costs. The tube wall of the diffuser 2 is provided with multiple rows of parallel circular steam exhaust holes 21, and geothermal steam is released through these steam exhaust holes 21.

[0074] Furthermore, porous sound-absorbing material 3 is filled between the diffuser 2 and the inner wall of the sound-absorbing pit 1 to adjust the steam emission flow rate, control the steam flow path, and ensure that the geothermal steam remains stable and laminar in the rock pit. The porosity and complex structure of the sound-absorbing material 3 are utilized to convert the energy of the steam into heat energy and sound energy dissipation through multiple reflections, scattering, and friction, thereby reducing the noise and emission pressure during emission, so as to give full play to the energy absorption and noise reduction effect of the sound-absorbing pit 1.

[0075] In a preferred embodiment, a plurality of silencer pits 1 are arranged in parallel, a diffuser 2 is provided in each silencer pit 1, and the diffusers 2 are arranged in parallel. When a silencer pit 1 needs maintenance, the silencer device can still discharge the entire designed steam flow. In this way, the silencer device is also designed to be modular and expandable, which is convenient for installation, maintenance and expansion, and improves the flexibility of the operation of the silencer device.

[0076] In a preferred embodiment, a protective cover 5 is provided between the diffuser 2 and the silencing material 3, which facilitates the inspection and replacement of the diffuser 2 and prevents the diffuser 2 from being crushed by the silencing material 3. The protective cover 5 can be made of metal or concrete, and is prefabricated in sections and installed in the middle of each silencing pit 1.

[0077] In a preferred embodiment, the cross section of the protective cover 5 is in the shape of the letter "n", with an opening at the bottom and an arc-shaped top, and the end of the diffuser 2 is closed, and the steam discharge hole 21 is arranged in the lower half of the diffuser 2. In this way, the steam can be guided downward and outward through the sound-absorbing material 3 in the sound-absorbing pit 1 to reduce the noise.

[0078] In a preferred embodiment, a drain port is provided at the lower portion of the side wall and / or the bottom wall of each silencing pit 1 for discharging condensed water generated by steam condensation, as well as rainwater, melted snow water, and the like.

[0079] In a preferred embodiment, the sound-absorbing material 3 is porous volcanic rock which is available locally at the geothermal wellhead. The density of the porous volcanic rock used in the present invention is less than 2600 kg / m 3 , porosity is greater than or equal to 0.25, and particle diameter is 50 to 300 mm.

[0080] Example 2

[0081] The core of the silencer is the porosity and filling density of the filled silencer material. The silencer effect of geothermal steam flowing through the silencer material is determined by design and multi-parameter optimization calculation. This embodiment provides a design method for a steam emission silencer for a geothermal power station. In this method, the minimum superficial fluidization velocity is calculated, and the steam flow rate is checked to be less than the minimum superficial fluidization velocity. Ensuring that the steam flow rate is lower than the minimum superficial fluidization velocity is the key to ensuring that the rock particles remain stable and are not overly washed or moved.

[0082] The calculation equation is as follows:

[0083]

[0084] in,

[0085] d p ——Diameter of the sound-absorbing material particles, in m;

[0086] ρ g ——Steam density, in kg / m 3 ;

[0087] ρ g ——Density of sound-absorbing material, in kg / m 3 ;

[0088] g——acceleration due to gravity, about 9.81m / s;

[0089] μ g ——dynamic viscosity of steam, in Pa·s or kg / (m·s);

[0090] ε——porosity of sound-absorbing material;

[0091] L——total length of silencer, in meters;

[0092] ——The pressure drop of steam flowing through the silencer, in Pa;

[0093] U mf ——minimum superficial fluidization velocity, in m / s;

[0094] After clarifying the flow rate, density, temperature and pressure parameters of steam emissions from geothermal power plants, the initial particle diameter of the silencer material is preliminarily set between 50 and 300 mm, and the porosity is assumed to be between 0.3 and 0.5. By adjusting key parameters such as the particle diameter, porosity, and size of the silencer, cyclic iterative calculations are performed. Based on the calculation results, the appropriate particle diameter, porosity, and size of the silencer are further adjusted to achieve the best performance.

[0095] In a preferred embodiment, in the equation:

[0096]

[0097] In a preferred embodiment, the design method further includes: obtaining the Reynolds number of the silencer material by calculating the flow state of the steam fluid in the silencer pit to determine whether the steam fluid flow is in a laminar flow, transitional flow or turbulent flow state. When the steam is in a laminar flow or a state close to laminar flow inside the silencer, it has a good energy reduction and noise reduction effect. The calculation formula of the Reynolds number of the silencer material is as follows:

[0098]

[0099] in,

[0100] ρ g ——Steam density, in kg / m 3

[0101] u g ——The flow velocity of steam in the muffler pit, in m / s;

[0102] d p ——Diameter of the sound-absorbing material particles, in m;

[0103] μ g ——Dynamic viscosity of steam, unit is Pa·s or kg / (m·s).

[0104] In a preferred embodiment, the flow velocity of geothermal steam in each section of the muffler is calculated by a formula, which is as follows:

[0105]

[0106] in,

[0107] ——Steam flow rate in the silencing pit, in kg / s;

[0108] υ su ——The speed of the steam flowing upward in the muffler pit, in m / s;

[0109] A pit ——Cross-sectional area of ​​the silencing pit, in m 2 ;

[0110]

[0111] in,

[0112] υ sd ——The speed at which steam flows downward through the diffuser, in m / s;

[0113] A db ——Diffuser cross-sectional area, in m 2 ;

[0114]

[0115] in,

[0116] υ sh ——The horizontal flow velocity of steam from the diffuser to the wall of the muffler pit, in m / s;

[0117] A rp ——The cross-sectional area of ​​the steam flow from the diffuser to the wall of the muffler pit, in m 2 .

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0119] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical content suggested above without departing from the scope of the technical solution of the present invention. The implementation scheme in the above embodiment can also be further combined or replaced. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the solution of the present invention.

Claims

1. A steam exhaust silencing device for a geothermal power station, characterized in that: include: at least one silencing pit; A diffuser, the wall of which is provided with a steam discharge hole, is arranged in the middle of the muffler pit, and the inlet of the diffuser is connected to the steam discharge port of the geothermal power station; A sound-absorbing material having pores is filled between the diffuser and the inner wall of the sound-absorbing pit; By adjusting the steam discharge flow rate, ensure that it is in a laminar flow state inside the silencer pit.

2. The steam exhaust silencing device for a geothermal power station according to claim 1, characterized in that: A protective cover is arranged between the diffuser and the sound-absorbing material.

3. The steam exhaust silencing device for a geothermal power station according to claim 2, characterized in that: The bottom of the protective cover is provided with an opening, and the steam discharge hole is arranged at the lower half of the diffuser.

4. The steam exhaust silencing device for a geothermal power station according to claim 1, characterized in that: A drainage outlet is provided at the lower part of the side wall and / or the bottom wall of each silencer pit.

5. The steam exhaust silencing device for a geothermal power station according to claim 1, characterized in that: The sound-absorbing material is porous volcanic rock.

6. The steam exhaust silencing device for a geothermal power station as claimed in claim 5, characterized in that: The density of the porous volcanic rock is less than 2600 kg / m 3 , porosity is greater than or equal to 0.25, and particle diameter is 50 to 300 mm.

7. A method for designing a steam exhaust silencing device for a geothermal power station as claimed in any one of claims 1 to 6, characterized in that: include: Calculate the minimum superficial fluidization velocity according to the following equation, and verify that the steam flow rate should be less than the minimum superficial fluidization velocity. in, d p ——Diameter of the sound-absorbing material particles, in m; ρ g ——Steam density, in kg / m 3 ; ρ p ——Density of sound-absorbing material, in kg / m 3 ; g——acceleration due to gravity, about 9.81m / s; μ g ——dynamic viscosity of steam, in Pa·s or kg / (m·s); ε——porosity of sound-absorbing material; L——total length of silencer, in meters; ——The pressure drop of steam flowing through the silencer, in Pa; U mf ——minimum superficial fluidization velocity, in m / s; By adjusting key parameters such as the particle diameter, porosity, and size of the silencer, cyclic iterative calculations are performed, and the appropriate particle diameter, porosity, and size of the silencer are further adjusted and selected based on the calculation results to achieve the best performance.

8. The design method of the steam exhaust silencing device of a geothermal power station as claimed in claim 7, characterized in that: In this equation:

9. The method for designing a steam exhaust silencing device for a geothermal power station as claimed in claim 7, characterized in that: Also includes: The Reynolds number of the silencer material is obtained by calculating the flow state of the steam fluid in the silencer pit, which is used to determine whether the steam fluid flow is in a laminar flow, transitional flow or turbulent flow state. The calculation formula of the Reynolds number of the silencer material is as follows: in, ρ p ——Steam density, in kg / m 3 u g ——The flow velocity of steam in the muffler pit, in m / s; d p ——Diameter of the sound-absorbing material particles, in m; μ g ——Dynamic viscosity of steam, unit is Pa·s or kg / (m·s).

10. The method for designing a steam exhaust silencing device for a geothermal power station as claimed in claim 9, characterized in that: The flow velocity of geothermal steam in each section of the silencer is calculated by the formula as follows: in, ——Steam flow rate in the silencing pit, in kg / s; υ su ——The speed of the steam flowing upward in the muffler pit, in m / s; A pit ——Cross-sectional area of ​​the silencing pit, in m 2 ; in, υ sd ——The speed at which steam flows downward through the diffuser, in m / s; A db ——Diffuser cross-sectional area, in m 2 ; in, υ sh ——The horizontal flow velocity of steam from the diffuser to the wall of the muffler pit, in m / s; A rp ——The cross-sectional area of ​​the steam flow from the diffuser to the wall of the muffler pit, in m 2 .

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