Duplex filter suitable for emergency diesel generating set

Abstract

The invention discloses a duplex filter suitable for an emergency diesel generating set. The duplex filter comprises a first filter, a second filter, an inlet pipeline, an outlet pipeline and a switching device, the first filter and the second filter are symmetrically arranged, the first filter comprises a first shell and a first filter element, the second filter comprises a second shell and a second filter element, the first shell and the second shell are made of Z2CN18-10, and the switching device is made of ZG04Cr19Ni10Mo2. The duplex filter suitable for the emergency diesel generating set can be applied to the emergency diesel generating set, and can effectively avoid the situation that nuclear-grade duplex filter products are lacked; the technical problem that fuel oil of the emergency diesel generator set can only be filtered through a fuel oil self-cleaning filter on a diesel engine main machine, so that the diesel generator set is stopped due to blockage, and a filter element is replaced or cleaned is solved, and the high engineering application value is achieved.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a dual filter suitable for emergency diesel generator sets. Background Technology

[0002] The function of emergency diesel generator sets in nuclear power plants is to provide emergency power to system equipment to mitigate the consequences of design-basis accidents during a LOOP (Loss of External Power) incident. The fuel system of these emergency diesel generator sets provides sufficient fuel to the emergency diesel generator sets within the nuclear power plant to ensure emergency operation. Each emergency diesel generator set is equipped with an independent fuel system, which mainly consists of a main fuel storage tank, a day fuel tank, a leak tank (if applicable), a fuel transfer pump (set), filters, flame arresters, a fuel booster pump, an oil cooler (if applicable), an oil-water separator (if applicable), valves, pipes, fittings, instruments, controllers, and mounting equipment (plunger pumps, fuel injectors, high-pressure fuel lines, self-cleaning filters, etc.).

[0003] The fuel system of emergency diesel generator sets requires a filter on the main fuel line between the fuel delivery pump and the daily fuel tank to filter the fuel and prevent impurities stored in the main fuel tank from entering the diesel engine and affecting its performance. This filter is a crucial component of the diesel engine fuel system, possessing safety functions (safety rating SC-3, standard level M3) and online maintenance capabilities. Currently, there are no mature products available domestically, necessitating urgent research and development to achieve the localization of diesel engine component supply.

[0004] Due to the lack of nuclear-grade dual-stage filter products, the fuel system of emergency diesel generator sets is not currently equipped with one. The fuel is filtered through the fuel self-cleaning filter on the diesel engine, which is prone to clogging and requires the diesel generator to be shut down for filter replacement or cleaning. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dual filter suitable for emergency diesel generator sets.

[0006] The technical solution adopted by the present invention to solve its technical problem is: to construct a dual filter suitable for emergency diesel generator sets, including a first filter, a second filter, an inlet pipe, an outlet pipe and a switching device; the first filter and the second filter are symmetrically arranged; The first filter includes a first housing and a first filter element. The interior of the first housing forms a first chamber and a second chamber. The first filter element is installed in the first chamber, and the inner cavity of the first filter element is connected to the second chamber. The first housing also has a first inlet pipe and a first outlet pipe. The first inlet pipe is connected to and communicates with the first chamber, and the first outlet pipe is connected to and communicates with the second chamber. The second filter includes a second housing and a second filter element. The interior of the second housing forms a third chamber and a fourth chamber. The second filter element is installed in the third chamber, and the inner cavity of the second filter element is connected to the fourth chamber. The second housing also has a second inlet pipe and a second outlet pipe. The second inlet pipe is connected to and communicates with the third chamber, and the second outlet pipe is connected to and communicates with the fourth chamber. The first housing and the second housing are made of Z2CN18-10 material, and the switching device is made of ZG04Cr19Ni10Mo2 material. The first inlet pipe and the second inlet pipe are connected to the inlet pipe, and the first outlet pipe and the second outlet pipe are connected to the outlet pipe. The switching device is installed on the inlet pipe and the outlet pipe. The switching device is used to switch the working state of the first filter and the second filter by rotating the handle.

[0007] In some embodiments, the first filter further includes a first exhaust valve, which is disposed on the first housing and communicates with the first chamber; the first exhaust valve is made of Z2CN18-10 material.

[0008] In some embodiments, the second filter further includes a second exhaust valve, which is disposed on the second housing and communicates with the third chamber; the second exhaust valve is made of Z2CN18-10 material.

[0009] In some embodiments, the first housing includes a first housing and a first cover plate, wherein the upper end of the first housing is an open structure and the first cover plate is used to seal and cover the upper end of the first housing; The inner wall surface of the first housing near its lower end is provided with an annular first support wall, which defines the first chamber and the second chamber of the inner cavity of the first housing. The first filter element has a first abutting block on its circumferential outer side near its lower end face. The lower end of the first filter element is inserted into the cavity of the first support wall, and the first abutting block abuts against the upper surface of the first support wall. At least one first sealing ring is provided between the circumferential side of the lower end of the first filter element and the inner wall surface of the cavity of the first support wall.

[0010] In some embodiments, the inner bottom surface of the first cover plate is further provided with a first limiting groove; The upper outer periphery of the first filter element is provided with a first limiting block. The first filter also includes a first elastic element. At least a portion of the first elastic element is sleeved on the upper end of the first filter element, and the two axial ends of the first elastic element respectively abut against the upper surface of the first limiting block and the inner end face of the first limiting groove.

[0011] In some embodiments, the second housing includes a second housing and a second cover plate, wherein the upper end of the second housing is an open structure and the second cover plate is used to seal and cover the upper end of the second housing; The inner wall surface of the second housing near its lower end is provided with an annular second support wall, which defines the third chamber and the fourth chamber within the inner cavity of the second housing. The second filter element has a second abutment block on the circumferential outer side near its lower end face. The lower end of the second filter element is inserted into the cavity of the second support wall, and the second abutment block abuts against the upper surface of the second support wall. At least one second sealing ring is provided between the circumferential side of the lower end of the second filter element and the inner wall surface of the cavity of the second support wall.

[0012] In some embodiments, the inner bottom surface of the second cover plate is further provided with a second limiting groove; The second filter element has a second limiting block on the outer periphery of its upper end. The second filter also includes a second elastic member. At least a portion of the second elastic member is sleeved on the upper end of the second filter element, and the two axial ends of the second elastic member respectively abut against the upper surface of the second limiting block and the inner end face of the second limiting groove.

[0013] In some embodiments, the dual filter for emergency diesel generator sets further includes a first support for supporting the first housing, and the first filter further includes a first discharge pipe connected to the bottom of the first housing and communicating with the second chamber.

[0014] In some embodiments, the dual filter for emergency diesel generator sets further includes a second support for supporting the second housing, and the second filter further includes a second discharge pipe connected to the bottom of the second housing and communicating with the fourth chamber.

[0015] In some embodiments, the dual filter for emergency diesel generator sets further includes a mounting plate on which the first support and the second support are detachably mounted.

[0016] In some embodiments, the first inlet pipe and the first outlet pipe are provided with a first differential pressure gauge; the second inlet pipe and the second outlet pipe are provided with a second differential pressure gauge.

[0017] In some embodiments, the first filter element and the second filter element are mesh filter elements.

[0018] Implementing this invention has the following beneficial effects: This dual filter for emergency diesel generator sets can be applied to emergency diesel generator sets, effectively avoiding the technical problem that due to the lack of nuclear-grade dual filter products, the fuel of emergency diesel generator sets can only be filtered through the fuel self-cleaning filter on the diesel engine host, which is prone to clogging and requires the diesel generator to be shut down for filter replacement or cleaning. It has high engineering application value. Attached Figure Description

[0019] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings: Figure 1 This is one of the structural schematic diagrams of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention; Figure 2 This is a second schematic diagram of the structure of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention; Figure 3 This is one of the partial structural schematic diagrams of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention; Figure 4 This is a second schematic diagram of a partial structure of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention; Figure 5 This is one of the parameter diagrams of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention; Figure 6 This is a second schematic diagram of the parameters of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention; Figure 7 This is the third schematic diagram of the parameters of a dual filter suitable for emergency diesel generator sets in some embodiments of the present invention. Detailed Implementation

[0020] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0021] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0023] See Figures 1 to 7 As shown, this invention discloses a dual filter (hereinafter referred to as a dual filter) suitable for emergency diesel generator sets. It can be applied to emergency diesel generator sets and effectively avoids the technical problem that, due to the lack of nuclear-grade dual filter products, the fuel in emergency diesel generator sets can only be filtered through the fuel self-cleaning filter on the diesel engine, which easily leads to clogging and generator shutdown for filter replacement or cleaning. This invention has high engineering application value. The overall height of the dual filter suitable for emergency diesel generator sets can be 1010mm.

[0024] See Figures 1 to 7 As shown, the dual filter for emergency diesel generator sets includes a first filter 10, a second filter 20, an inlet pipe 30, an outlet pipe 40, and a switching device 50; the first filter 10 and the second filter 20 are arranged symmetrically.

[0025] The first filter 10 includes a first housing 11 and a first filter element 12. The interior of the first housing 11 forms a first chamber 11a and a second chamber 11b. The first chamber 11a is located above the second chamber 11b. The first filter element 12 is installed in the first chamber 11a and its inner cavity is connected to the second chamber 11b. The first housing 11 also has a first inlet pipe 1111 and a first outlet pipe 1112. The first inlet pipe 1111 is connected to and communicates with the first chamber 11a, and the first outlet pipe 1112 is connected to and communicates with the second chamber 11b.

[0026] The second filter 20 includes a second housing 21 and a second filter element 22. The interior of the second housing 21 forms a third chamber 21a and a fourth chamber 21b. The third chamber 21a is located above the fourth chamber 21b. The second filter element 22 is installed in the third chamber 21a, and the inner cavity of the second filter element 22 is connected to the fourth chamber 21b. The second housing 21 also has a second inlet pipe 2111 and a second outlet pipe 2112. The second inlet pipe 2111 is connected to and communicates with the third chamber 21a, and the second outlet pipe 2112 is connected to and communicates with the fourth chamber 21b. The first housing 11 and the second housing 21 are made of Z2CN18-10 material, and the switching device 50 is made of ZG04Cr19Ni10Mo2 material. The safety classification meets the nuclear level 3 (SC-3) and standard level (M3).

[0027] The first inlet pipe 1111 and the second inlet pipe 2111 are connected to the inlet pipe 30, and the first outlet pipe 1112 and the second outlet pipe 2112 are connected to the outlet pipe 40. The switching device 50 is installed on the inlet pipe 30 and the outlet pipe 40. The switching device 50 is used to switch the operating states of the first filter 10 and the second filter 20 by rotating a handle. For example, the switching device 50 can switch the inlet pipe 30 to be connected to the first inlet pipe 1111 and the outlet pipe 40 to be connected to the first outlet pipe 1112, or the switching device 50 can switch the inlet pipe 30 to be connected to the second inlet pipe 2111 and the outlet pipe 40 to be connected to the second outlet pipe 2112. The switching device 50 can be a switching valve, such as a three-way switching valve. The switching states of the switching device 50 can be found in [reference needed]. Figure 6 As shown.

[0028] like Figure 1 As shown, in some embodiments, the first filter 10 further includes a first exhaust valve 13, which is disposed on the first housing 11 and communicates with the first chamber 11a; the first exhaust valve 13 is made of Z2CN18-10 material. The specifications of the first inlet pipe 1111, the second inlet pipe 2111, the first outlet pipe 1112, and the second outlet pipe 2112 can be DN40.

[0029] like Figure 1 As shown, in some embodiments, the second filter 20 further includes a second exhaust valve 23, which is disposed on the second housing 21 and is connected to the third chamber 21a; the material of the second exhaust valve 23 is Z2CN18-10.

[0030] like Figure 1 and Figure 3 As shown, in some embodiments, the first housing 11 includes a first shell 111 and a first cover plate 112. The first shell 111 is generally cylindrical, with an open upper end. The first cover plate 112 is used to seal and cover the upper end of the first shell 111. Further, the first cover plate 112 is used to seal and cover the upper end of a flange on the first shell 111. For example, the first cover plate 112 and the upper end of the first shell 111 can be detachably connected via a first flange assembly. The first flange assembly may include a first flange and a second flange. For example, the upper end of the first shell 111 has a first flange, and the first cover plate 112 has a second flange. The first flange and the second flange are connected and fixed by fasteners, including but not limited to fastening bolts or fastening screws. The detachable connection between the first shell 111 and the first cover plate 112 facilitates the disassembly and replacement of the first filter element 12 or the maintenance of the internal components of the first shell 111. The first cover plate 112 may also be provided with several first lifting lugs 16, which facilitate the lifting of the first filter 10. The first housing 111, the first cover plate 112 and the first flange assembly can all be made of nuclear-grade forged stainless steel material Z2CN18-10.

[0031] The inner wall surface of the first housing 111 near its lower end is provided with an annular first support wall 113, which defines the inner cavity of the first housing 111 into the first chamber 11a and the second chamber 11b.

[0032] The first filter element 12 has a first abutment block 121 on its circumferential outer side near its lower end. The lower end of the first filter element 12 is inserted into the cavity of the first support wall 113, and the first abutment block 121 abuts against the upper surface of the first support wall 113. At least one first sealing ring 122 is provided between the circumferential side of the lower end of the first filter element 12 and the inner wall of the cavity of the first support wall 113. The first abutment block 121 allows for quick installation and fixation of the first filter element 12, and the first sealing ring 122 improves the sealing performance. Preferably, the circumferential side of the lower end of the first filter element 12 has at least one first sealing groove, and the first sealing ring 122 is disposed in the first sealing groove. The first sealing ring 122 may include, but is not limited to, silicone sealing rings and rubber sealing rings.

[0033] like Figure 1 and Figure 3 As shown, in some embodiments, the inner bottom surface of the first cover plate 112 is further provided with a first limiting groove 1121, and the outer periphery of the upper end of the first filter element 12 is provided with a first limiting block 123. The first limiting block 123 can be an annular structure, and the first limiting block 123 is fixed together with the upper end of the first filter element 12, for example, by welding. Alternatively, the first limiting block 123 can be an annular structure, and the first limiting block 123 is detachably connected to the upper end of the first filter element 12. For example, the upper end of the first filter element 12 is provided with an external threaded surface, and the inner cavity of the first limiting block 123 is provided with an internal threaded surface, and the two are threadedly connected and fixed.

[0034] The first filter 10 also includes a first elastic element 14, at least a portion of which is sleeved on the upper end of the first filter element 12. The axial ends of the first elastic element 14 respectively abut against the upper surface of the first limiting block 123 and the inner end face of the first limiting groove 1121. The first elastic element 14 may be, but is not limited to, a helical columnar spring. The first limiting block 123 and the first limiting groove 1121 can axially limit the first elastic element 14, preventing it from shifting. The first elastic element 14 provides elastic force to the first filter element 12, ensuring that the lower end of the first filter element 12 is always fixed to the first support wall 113, preventing the first filter element 12 from shaking or shifting when impacted by oil, and improving the installation stability of the first filter element 12.

[0035] like Figure 1 and Figure 4As shown, in some embodiments, the second housing 21 includes a second housing 211 and a second cover plate 212. The second housing 211 is generally cylindrical, with an open upper end. The second cover plate 212 is used to seal and cover the upper end of the second housing 211. Further, the second cover plate 212 is used to seal and cover the upper end of the flange of the second housing 211. For example, the second cover plate 212 and the upper end of the second housing 211 can be detachably connected via a second flange assembly. The second flange assembly may include a third flange and a fourth flange. For example, the upper end of the second housing 211 has a third flange, and the second cover plate 212 has a fourth flange. The third flange and the fourth flange are connected and fixed by fasteners, including but not limited to fastening bolts or fastening screws. The detachable connection between the second housing 211 and the second cover plate 212 facilitates the disassembly and replacement of the second filter element 22 or the maintenance of the internal components of the second housing 211. The second cover plate 212 may also be provided with several second lifting lugs 26, which facilitate the lifting of the second filter 20. The second housing 211, the second cover plate 212 and the second flange assembly can all be manufactured from nuclear-grade forged stainless steel material Z2CN18-10.

[0036] The inner wall surface of the second housing 211 near its lower end is provided with an annular second support wall 213, which defines the inner cavity of the second housing 211 into the third chamber 21a and the fourth chamber 21b.

[0037] The second filter element 22 has a second abutment block 221 on its circumferential outer side near its lower end. The lower end of the second filter element 22 is inserted into the cavity of the second support wall 213, and the second abutment block 221 abuts against the upper surface of the second support wall 213. At least one second sealing ring 222 is provided between the circumferential side of the lower end of the second filter element 22 and the inner wall of the cavity of the second support wall 213. The second abutment block 221 allows for quick installation and fixation of the second filter element 22, and the second sealing ring 222 improves the sealing performance. Preferably, the circumferential side of the lower end of the second filter element 22 has at least one second sealing groove, and the second sealing ring 222 is disposed in the second sealing groove. The second sealing ring 222 may include, but is not limited to, silicone sealing rings and rubber sealing rings.

[0038] like Figure 1 and Figure 4As shown, in some embodiments, the inner bottom surface of the second cover plate 212 is further provided with a second limiting groove 2121. A second limiting block 223 is provided on the outer periphery of the upper end of the second filter element 22. The second limiting block 223 can be an annular structure, and it is fixed to the upper end of the second filter element 22, for example, by welding. Alternatively, the second limiting block 223 can be an annular structure, and it is detachably connected to the upper end of the second filter element 22. For example, the upper end of the second filter element 22 has an external threaded surface, and the inner cavity of the second limiting block 223 has an internal threaded surface; the two are threadedly connected and fixed.

[0039] The second filter 20 also includes a second elastic element 24, at least a portion of which is sleeved on the upper end of the second filter element 22, and both axial ends of the second elastic element 24 abut against the upper surface of the second limiting block 223 and the inner end face of the second limiting groove 2121, respectively. The second elastic element 24 may be, but is not limited to, a helical columnar spring. The second limiting block 223 and the second limiting groove 2121 can axially limit the second elastic element 24, preventing it from shifting. The second elastic element 24 provides elastic force to the second filter element 22, ensuring that the lower end of the second filter element 22 is always fixed to the second support wall 213, preventing the second filter element 22 from shaking or shifting when impacted by oil, and improving the installation stability of the second filter element 22.

[0040] like Figure 1 and Figure 3 As shown, in some embodiments, the dual filter for emergency diesel generator sets further includes a first support 60 for supporting the first housing 11. The first support 60 may be a cylindrical structure. The first filter 10 also includes a first discharge pipe 15 connected to the bottom of the first housing 11 and communicating with the second chamber 11b. The first discharge pipe 15 may pass through the circumferential sidewall of the first support 60. The end of the first discharge pipe 15 may be provided with a first connector, which may be, but is not limited to, a flange connector or a quick connector, to facilitate connection with components such as a waste fuel tank. Alternatively, the first discharge pipe 15 may be provided with a first control valve.

[0041] like Figure 1 and Figure 4As shown, in some embodiments, the dual filter for emergency diesel generator sets further includes a second support 70 for supporting the second housing 21. The second support 70 may be a cylindrical structure. The second filter 20 also includes a second discharge pipe 25 connected to the bottom of the second housing 21 and communicating with the fourth chamber 21b. The second discharge pipe 25 may pass through the circumferential sidewall of the second support 70, and the end of the second discharge pipe 25 may be provided with a second connector, which may be, but is not limited to, a flange connector or a quick connector, for connection to components such as a waste fuel tank. Alternatively, the second discharge pipe 25 may be provided with a second control valve.

[0042] In some embodiments, both the first discharge pipe 15 and the second discharge pipe 25 can be manufactured using nuclear-grade forged steel material Z2CN18-10. The specifications of the first discharge pipe 15 and the second discharge pipe 25 can be DN15.

[0043] like Figure 1 As shown, in some embodiments, the dual filter suitable for emergency diesel generator sets further includes a mounting plate 80. The first support 60 and the second support 70 are detachably mounted on the mounting plate 80. The mounting plate 80 can be a rectangular plate structure. The base plates of the first support 60 and the second support 70 are detachably connected to the mounting plate 80, for example, by threaded connection, and can be fixed by fastening bolts or screws. No specific limitation is made here. The first support 60 and the second support 70 can be manufactured from nuclear-grade forged stainless steel material Z2CN18-10, and the mounting plate 80 can also be manufactured from nuclear-grade forged stainless steel material Z2CN18-10. The length of the mounting plate 80 can be 820mm and the width can be 284mm.

[0044] In some embodiments, a first differential pressure gauge is provided between the first inlet pipe 1111 and the first outlet pipe 1112; a second differential pressure gauge is provided between the second inlet pipe 2111 and the second outlet pipe 2112. The differential pressure gauges can be used to detect the pressure difference between the inlet and outlet. When the pressure difference data does not meet the requirements, the filter element needs to be replaced.

[0045] Of course, the first inlet pipe 1111 and the first outlet pipe 1112 may be equipped with a pressure gauge and a flow meter respectively. Similarly, the second inlet pipe 2111 and the second outlet pipe 2112 may be equipped with a pressure gauge and a flow meter respectively. No specific limitation is made here.

[0046] In some embodiments, the first filter element 12 and the second filter element 22 are mesh filter elements.

[0047] In some embodiments, the dual filter for emergency diesel generator sets adopts a compact, small-sized, flow-pressure-pulsation-free, and high-efficiency dual-cylinder, dual-cut structure.

[0048] 1) The thickness design of the first outer shell 11 and the second outer shell 21 follows a conservative principle and considers necessary safety margins, and can be carried out according to the calculation formula and requirements as follows: a. The wall thickness of the first outer shell 11 and the second outer shell 21 is calculated using the value t1. For carbon steel, the thickness is not less than 6mm, and for stainless steel, it is not less than 3mm. In this application, the thickness of the first outer shell 11 and the second outer shell 21 is 4mm, and their diameter is 168.3mm. Of course, the dimensions of the first outer shell 11 and the second outer shell 21 can also be selected and set according to requirements, and no specific limitation is made here.

[0049] b. Circumferential stress calculation: t1 = PR / (kS - 0.6P); Longitudinal stress calculation: t1 = PR / (2kS + 0.4P), the maximum value of the two is taken for the calculated thickness. Where P is the design pressure (MPa), R is the inner radius of the cylinder (mm), S is the allowable stress of the material (MPa) multiplied by a coefficient of 0.85, and k is a correction coefficient, taken as 1; the design pressure P is generally not lower than the maximum working pressure, for example, in this scheme the maximum working pressure is 0.6MPa, and the design pressure is taken as 1.0MPa.

[0050] c. The nominal thickness is the calculated thickness plus the corrosion allowance, then rounded up. Rounding up means rounding the value upwards.

[0051] 2) Safety classification and main performance parameters. The performance parameters of the dual filter meet the functional requirements of typical emergency diesel generator sets. The safety classification and main performance parameters are shown in Tables 1 and 2, forming a dual filter suitable for emergency diesel generator sets.

[0052] 3) The dual filter suitable for emergency diesel generator sets has a symmetrical double-cylinder structure and can be fixed to the civil foundation by mounting plate 80.

[0053] 4) Working principle of the dual-filter. The dual-filter adopts a dual-cylinder structure and a switching device, enabling online maintenance and filter element replacement without affecting the normal operation of the fuel system. First, the switching device selects either the first filter 10 or the second filter 20. Fuel from the upstream pipeline enters the first housing 11 or the second housing 21 through the inlet pipe. After filtration by the filter element, the fuel flows through the inner cavity of the filter element and converges at the lower part of the first housing 11 or the second housing 21, and then connects to the downstream pipeline through the outlet pipe. During the initial fuel intake, the first vent valve 13 or the second vent valve 23 at the top can be opened to vent the air inside the first housing 11 or the second housing 21. Differential pressure gauges can be installed on the inlet and outlet pipes of the first filter 10 and the second filter 20. When the pressure drop reaches the point where the filter element needs to be replaced, the switching device 50 is operated to switch to the other filter. Fuel on the side to be maintained can be drained through the drain pipe. After opening the top cover, the filter element can be removed and replaced.

[0054] 5) Material selection for the dual filter. The housing, flange, cover plate, discharge pipe, support, and mounting plate of the dual filter of the present invention can all be manufactured using nuclear-grade forged steel material Z2CN18-10. The switching device 50 is manufactured using nuclear-grade casting material ZG04Cr19Ni10Mo2. The first exhaust valve 13 and the second exhaust valve 23 are nuclear-grade valves made of material Z2CN18-10.

[0055] 6) Raw material re-inspection. Raw materials shall be inspected and re-inspected in batches. For example, forgings shall be composed of forgings with the same melting furnace number, the same manufacturing process, the same heat treatment in the same furnace, and the same heat treatment for no more than 8 hours of continuous operation, and with similar dimensions.

[0056] Test specimens should be cut from forgings, with the main forging direction appropriately marked, and cut using machining methods. Each specimen should be machined to include: one room temperature tensile specimen and one hardness specimen, which can also serve as samples for finished product analysis.

[0057] Chemical composition retest: For forging samples, X-ray fluorescence spectrometry can be used for quantitative elemental analysis, and the results can be compared with the chemical composition of the material standard (finished product analysis) to determine whether it is within the allowable range.

[0058] Mechanical property retesting: For forging samples, sample blanks can be cut from the forgings and machined into proportional or non-proportional samples. Room temperature tensile tests are then conducted to determine the specified plastic extension strength, tensile strength, elongation after fracture, reduction of area, and hardness. These values ​​are then compared with the mechanical properties of the material standard to determine whether they are within the allowable range.

[0059] 7) After processing, the surface is subjected to penetrant testing and weld radiographic testing.

[0060] Penetrant testing generally uses the fluorescence method. The steps of penetrant testing are: pretreatment, application of penetrant, removal of excess penetrant, drying, application of developer, observation and evaluation, and post-processing.

[0061] During fluorescence penetrant testing, the assessment of defect display should be conducted in a dark room or dark place, with visible light illuminance not exceeding 20 lx, and the irradiance of the surface of the inspected workpiece ≥ 1000 μW / cm2. During self-development, the irradiance of the surface of the inspected workpiece should be ≥ 3000 μW / cm2.

[0062] Displays with a size ≥ 2mm should be recorded. Linear displays, circular displays with a size greater than 5mm, three or more displays on the same straight line with an edge distance of less than 3mm between two displays, and rectangular areas with severe defects should be removed or repaired; otherwise, they will be deemed unqualified.

[0063] Radiographic testing requires that the inspection length of each weld be no less than 20% of the total weld length and no less than 250mm (if the total length is less than 250mm, the actual length shall be used) be photographed. Cracks, lack of fusion, incomplete penetration, undercut, any porosity longer than 6mm, and any slag inclusions longer than 6mm are not allowed.

[0064] 8) Performance qualification tests include chamber water pressure test, initial resistance test, filtration efficiency and filtration accuracy test, dual filter pressure change test, switching device leakage rate test, seismic test of equipment according to 0.3g envelope spectrum, and post-test disassembly and inspection.

[0065] Cavity hydrostatic test: Each housing of the dual-stage filter must undergo a hydrostatic test, with the test pressure not less than 1.5 times the design pressure. Acceptance criteria: No pressure drop, no leakage, no visible deformation, and no abnormal noise during the test.

[0066] Original resistance test: Install the filter housing in the dual-filter test system (existing technology) and exhaust all gas inside the housing.

[0067] At a test temperature ≤60℃, the test solution is circulated at a rated flow rate of 166.7 L / min in the dual-stage filter test system to maintain the viscosity of the test solution within 2.5~8.0 mm² / s. The temperature and the pressure drop between the inlet and outlet of the dual-stage filter are recorded; this is the initial resistance of the dual-stage filter. The initial resistance of the dual-stage filter should not exceed 30 kPa.

[0068] Filtration efficiency and filtration accuracy tests: Filtration efficiency and filtration accuracy tests shall be conducted in accordance with the test methods specified in the relevant filter specifications. The automatic particle counter of the test system shall be calibrated.

[0069] Dual-stage filter pressure variation test: Pour clean hydraulic oil at its rated working pressure into the dual-stage filter. Use a switching valve to transfer the hydraulic oil from one filter chamber to the other. Check for any jamming during the switching process and observe the pressure changes in the inlet pipe. The switching valve should not jam or stop supplying oil during operation; the inlet pressure should be less than or equal to 1.5 times the maximum working pressure.

[0070] Leakage rate test of the switching device: The leakage rate test of the switching device is conducted when the hydraulic oil pressure is the working pressure. First, place the switching device 50 in the middle position, fill both filters with hydraulic oil, then rotate the switching device 50 to the working position of any filter and open the vent valve of the other filter. Hydraulic oil is introduced into the dual filter, and the volume of hydraulic oil leaking from the vent valve per minute is measured using a measuring cup. Then, the switching device 50 is rotated to the working position of the other filter, and the volume of hydraulic oil leaking from the other filter per minute is measured using the same method.

[0071] The leakage rate standard requirement for the switching device is: when the switching device 50 is switching under working pressure conditions, the leakage rate should be less than 0.4DN.mL / min. Note: DN is the nominal diameter of the filter inlet in millimeters.

[0072] The equipment was subjected to seismic testing according to the 0.3g envelope spectrum: Test method: The dual filter was installed on the seismic test bench, and the dual filter was connected to the external accessories of the seismic test bench through a hose. The external drive device was started, and the inlet pressure of the dual filter was adjusted to the rated requirements. Each dual filter required 5 low-level seismic simulation tests, of which 3 were applied during the operation of the dual filter and 2 were applied in the low-level seismic simulation test; 1 safe shutdown seismic simulation test. The duration of each applied acceleration was not less than 30 seconds, and the duration of the strong signal was not less than 15 seconds.

[0073] Acceptance criteria: During the earthquake test, the pressure drop, leakage, and deformation of the dual-filter must be monitored.

[0074] Post-test disassembly and inspection: After all test items are completed, the dual filter is disassembled and inspected to check whether the filter element, sealing ring, and outer shell are deformed or damaged, and the results are recorded in the test report.

[0075] Table 1. Performance parameters and main materials of dual filters suitable for emergency diesel generator sets Table 2. Classification of Dual Filters Applicable to Emergency Diesel Generator Sets The dual filter proposed in this invention for emergency diesel generator sets was determined based on domestic engineering needs and design and manufacturing capabilities, through continuous exploration and scheme comparison. It can effectively avoid the technical problem that due to the lack of nuclear-grade dual filter products, the fuel of emergency diesel generator sets can only be filtered through the fuel self-cleaning filter on the diesel engine host, which is prone to clogging and requires the diesel generator to be shut down for filter replacement or cleaning. It has high engineering application value.

[0076] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A duplex filter suitable for use in an emergency diesel generator set, characterised in that, The utility model provides a filter device, including first filter (10), second filter (20), import pipeline (30), export pipeline (40) and switching device (50), first filter (10) with second filter (20) symmetry is arranged, The first filter (10) includes a first housing (11) and a first filter element (12), the first housing (11) forms a first chamber (11a) and a second chamber (11b) inside, the first filter element (12) is installed in the first chamber (11a), and the inner cavity of the first filter element (12) is in communication with the second chamber (11b); the first housing (11) is also provided with a first inlet pipe (1111) and a first outlet pipe (1112), the first inlet pipe (1111) is connected and communicated with the first chamber (11a), and the first outlet pipe (1112) is connected and communicated with the second chamber (11b); The second filter (20) includes a second housing (21) and a second filter element (22), the second housing (21) forms a third chamber (21a) and a fourth chamber (21b) inside, the second filter element (22) is installed in the third chamber (21a), and the inner cavity of the second filter element (22) is in communication with the fourth chamber (21b); the second housing (21) is also provided with a second inlet pipe (2111) and a second outlet pipe (2112), the second inlet pipe (2111) is connected and communicated with the third chamber (21a), and the second outlet pipe (2112) is connected and communicated with the fourth chamber (21b); the manufacturing material of the first housing (11) and the second housing (21) is Z2CN18-10, and the manufacturing material of the switching device (50) is ZG04Cr19Ni10Mo2; The first inlet pipe (1111), the second inlet pipe (2111) and the import pipeline (30) are connected, the first outlet pipe (1112), the second outlet pipe (2112) and the export pipeline (40) are connected, the switching device (50) is installed on the import pipeline (30) and the export pipeline (40), and the switching device (50) is used for switching the working state of the first filter (10) and the second filter (20) by rotating the handle.

2. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The first filter (10) further includes a first exhaust valve (13), the first exhaust valve (13) is provided on the first housing (11), and the first exhaust valve (13) is in communication with the first chamber (11a); the manufacturing material of the first exhaust valve (13) is Z2CN18-10.

3. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The second filter (20) further includes a second exhaust valve (23), the second exhaust valve (23) is provided on the second housing (21), and the second exhaust valve (23) is in communication with the third chamber (21a); the manufacturing material of the second exhaust valve (23) is Z2CN18-10.

4. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The first shell (11) comprises a first shell body (111) and the first cover plate (112), the upper end of the first shell body (111) is an open structure, and the first cover plate (112) is used for sealingly covering the upper end of the first shell body (111); An annular first supporting wall (113) is arranged on the inner wall surface of the inner cavity of the first shell body (111) close to the lower end thereof, and the first supporting wall (113) divides the inner cavity of the first shell body (111) into the first chamber (11a) and the second chamber (11b); A first abutting block (121) is arranged on the circumferential outer side surface of the first filter element (12) close to the lower end surface thereof, the lower end of the first filter element (12) is inserted into the through cavity of the first supporting wall (113), the first abutting block (121) abuts against the upper surface of the first supporting wall (113), and at least one first sealing ring (122) is arranged between the circumferential side surface of the lower end of the first filter element (12) and the inner wall surface of the through cavity of the first supporting wall (113).

5. The duplex filter suitable for use in an emergency diesel generator set according to claim 4, characterized in that, The inner bottom surface of the first cover plate (112) is further provided with a first limiting groove (1121); The outer periphery of the upper end of the first filter element (12) is provided with a first limiting block (123), and the first filter (10) further comprises a first elastic member (14), at least part of the first elastic member (14) is sleeved on the upper end of the first filter element (12), and the axial two ends of the first elastic member (14) abut against the upper surface of the first limiting block (123) and the inner end surface of the first limiting groove (1121) respectively.

6. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The second shell (21) comprises a second shell body (211) and a second cover plate (212), the upper end of the second shell body (211) is an open structure, and the second cover plate (212) is used for sealingly covering the upper end of the second shell body (211); An annular second supporting wall (213) is arranged on the inner wall surface of the inner cavity of the second shell body (211) close to the lower end thereof, and the second supporting wall (213) divides the inner cavity of the second shell body (211) into the third chamber (21a) and the fourth chamber (21b); A second abutting block (221) is arranged on the circumferential outer side surface of the second filter element (22) close to the lower end surface thereof, the lower end of the second filter element (22) is inserted into the through cavity of the second supporting wall (213), the second abutting block (221) abuts against the upper surface of the second supporting wall (213), and at least one second sealing ring (222) is arranged between the circumferential side surface of the lower end of the second filter element (22) and the inner wall surface of the through cavity of the second supporting wall (213).

7. The duplex filter suitable for use in an emergency diesel generator set according to claim 6, characterized in that, The inner bottom surface of the second cover plate (212) is further provided with a second limiting groove (2121); The outer periphery of the upper end of the second filter element (22) is provided with a second limiting block (223), and the second filter (20) further comprises a second elastic member (24), at least part of the second elastic member (24) is sleeved on the upper end of the second filter element (22), and the axial two ends of the second elastic member (24) respectively abut against the upper surface of the second limiting block (223) and the inner end surface of the second limiting groove (2121).

8. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The double filter suitable for the emergency diesel generating set further comprises a first support (60) for supporting the first shell (11), and the first filter (10) further comprises a first discharge pipeline (15) connected with the bottom of the first shell (11) and communicating with the second chamber (11b).

9. Double filter suitable for emergency diesel generator sets according to claim 8, characterized in that, The double filter suitable for the emergency diesel generating set further comprises a second support (70) for supporting the second shell (21), and the second filter (20) further comprises a second discharge pipeline (25) connected with the bottom of the second shell (21) and communicating with the fourth chamber (21b).

10. The duplex filter suitable for use in an emergency diesel generator set according to claim 9, characterized in that, The double filter suitable for the emergency diesel generating set further comprises a mounting plate (80), and the first support (60) and the second support (70) are detachably mounted on the mounting plate (80).

11. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The first inlet pipe (1111) and the first outlet pipe (1112) are provided with a first differential pressure gauge, and the second inlet pipe (2111) and the second outlet pipe (2112) are provided with a second differential pressure gauge.

12. The duplex filter suitable for use in an emergency diesel generator set according to claim 1, characterized in that, The first filter element (12) and the second filter element (22) are mesh filter elements.

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