Compact flow resistance measurement structure and flow resistance measurement method

Abstract

The application discloses a compact flow resistance measuring structure and a flow resistance measuring method. The compact flow resistance measuring structure comprises an inlet measuring section, an inlet sealing ring, a flow guide, an outlet measuring section, an outlet sealing rubber gasket, an outlet sealing ring, a fastening bolt and a limiting cap. The flow guide introduces the medium into the filter element for filtration and then discharges the medium. The structure of the flow guide is designed with an annular cavity, an annular protrusion and a shunt groove to realize correct flow of the medium. The combination of the inlet sealing ring, the outlet sealing rubber gasket and the outlet sealing ring realizes complete isolation of the inflow medium and the outflow medium. The compact flow resistance measuring structure and the method can adapt to the structural features of the filter element, accurately measure the flow resistance of the filter element and avoid damage of the filter element.

Description

Technical Field

[0001] This invention relates to a flow resistance measurement structure and method, used to conduct resistance performance tests on filter elements to assess whether the performance indicators of the filter elements meet user requirements, and belongs to the field of aviation performance testing and inspection. Background Technology

[0002] Aviation oil filters are important components of engine accessories, with the filter element being a key part. The filter element removes metal particles and impurities from the oil, ensuring the cleanliness of the oil circulation system. One of the main performance indicators of the filter element is its pressure drop characteristics and flow capacity.

[0003] Pressure drop characteristics refer to the pressure loss generated by oil passing through the filter element. The higher the filter element precision, the greater the pressure drop. The larger the effective filtration area of ​​the filter element, the smaller the pressure drop.

[0004] Flow capacity refers to the maximum flow rate that is allowed to pass through the filter element under a certain pressure difference.

[0005] Once a filter element is designed and manufactured, flow rate and resistance are key performance indicators for measuring its flow capacity, and the accuracy of the flow resistance measurement is directly related to the structure used. Traditional flow resistance measurement devices are bulky, have complex wiring, and are not suitable for... Figure 13 The filter element structure in the filter cartridge is prone to significant measurement errors, leading to inaccurate flow resistance measurements. Furthermore, improper filter element positioning and fixing structures can easily cause deformation and damage during the measurement process. Summary of the Invention

[0006] To address the problems existing in the background technology, the present invention aims to provide a compact flow resistance measurement structure and method, which occupies little space, has a simple structure, a stable testing process, and is not easily affected by media impact. Based on the structural characteristics of the filter screen in the filter element, it can improve the flow conduction capacity, improve the accuracy of flow resistance measurement, avoid media mixing at the inlet and outlet due to the structural characteristics of the filter element, and further avoid deformation and damage to the filter element during the testing process.

[0007] To solve the above problems, the present invention adopts the following solution:

[0008] A compact flow resistance measurement structure is used to measure the flow resistance of a filter element. The filter element mainly consists of an upper frame, an outer shell, a filter screen layer, and a lower frame. The filter screen layer is fixed to the outer shell via the upper and lower frames at its axial ends. The medium flows in radially and out axially along the filter screen layer. The compact flow resistance measurement structure includes...

[0009] The guide fluid is a rotating structure and includes a medium inlet channel, a medium outlet channel, an annular cavity, an annular protrusion, and a diversion groove. The medium inlet channel is located in a plane perpendicular to the rotation axis of the guide fluid, and the medium outlet channel is coaxial with the rotation axis. The annular cavity is connected to the medium outlet channel and the medium inlet channel, and is coaxial with the medium outlet channel. The guide fluid is sleeved on the filter element shell at one end corresponding to the upper frame of the filter element through the annular cavity. The annular protrusion is located in the annular cavity, and the inner ring of the annular protrusion forms part of the medium outlet channel. The annular protrusion is inserted into the upper frame of the filter element. A diversion groove is provided between the outlet of the medium inlet channel and the upper frame of the filter element. The diversion groove is perpendicular to the rotation axis of the guide fluid and extends bidirectionally from the outlet of the medium inlet channel along a circle concentric with the annular protrusion. Both ends of the extended diversion groove are arc-shaped, and the central angle corresponding to the diversion groove is less than 180°.

[0010] An inlet measuring section, wherein the first axial end of the inlet measuring section is coaxially connected to the inlet of the medium inlet channel;

[0011] The outlet measuring section has its first axial end coaxially connected to the outlet of the medium outlet channel;

[0012] An imported sealing ring is disposed between the inner wall of the annular cavity and the outer wall of the filter element housing.

[0013] The outlet sealing gasket is fitted onto the outer surface of the annular protrusion, with one end face of the outlet sealing gasket in close contact with the end face of the upper skeleton of the filter element and the other end face in close contact with the fluid guide, thereby achieving an end face seal perpendicular to the rotation axis of the fluid guide.

[0014] An outlet sealing ring is disposed between the upper skeleton of the filter element and the outer surface of the annular protrusion to achieve radial sealing in a plane perpendicular to the rotation axis of the fluid guide.

[0015] Furthermore, the inlet sealing ring and the outlet sealing ring are located in the same plane, and this plane is perpendicular to the rotation axis of the guide fluid.

[0016] Furthermore, the inlet sealing ring and the outlet sealing ring are sealing rings with circular cross-sections, and the outlet sealing gasket is a sealing gasket with a rectangular cross-section.

[0017] As an alternative, the compact flow resistance measurement structure also includes,

[0018] A limiting cap is placed on the outer shell of the filter element at one end corresponding to the lower frame of the filter element.

[0019] Tighten the bolts;

[0020] Mounting ear, the mounting ear being disposed on the fluid guide;

[0021] The two ends of the fastening bolt are connected to the mounting lug and the limiting cap respectively, so that the filter element is fixed between the fluid guide and the limiting cap.

[0022] Alternatively, the inlet measuring section and the outlet measuring section are welded to the fluid guide.

[0023] Alternatively, both the inlet and outlet measuring sections are equipped with temperature measuring connectors. The axis of the temperature measuring connector forms an angle of ° with the axes of the inlet and outlet measuring sections. When a temperature measuring probe is inserted into the temperature measuring connector, the projection of the insertion direction of the temperature measuring probe onto the axes of the inlet and outlet measuring sections includes an axial component, which is opposite to the flow direction of the medium in the inlet and outlet measuring sections.

[0024] Alternatively, pressure testing connectors are provided on both the inlet and outlet measuring sections. The axis of the pressure testing connector is perpendicular to the axis of the inlet and outlet measuring sections, and the straight-line distance from the pressure testing connector to the fluid guide is less than the straight-line distance from the temperature testing connector to the fluid guide.

[0025] Alternatively, the outer side of the second axial end of the inlet measuring section and the outlet measuring section has a conical structure, and a sealing ring is provided on the large-diameter end face of the conical structure.

[0026] Alternatively, the inner wall of the annular cavity has internal threads, and the outer surface of the filter element housing has external threads, and the two are connected by threads.

[0027] A method for measuring the flow resistance of a filter cartridge using the aforementioned compact flow resistance measurement structure with a limiting cap, fastening bolts, and mounting ears, comprising:

[0028] Adjust the orientation of the guide fluid so that the axes of the inlet measuring section, the outlet measuring section, and the guide fluid are all parallel to the horizontal plane. Insert one end of the filter element corresponding to the upper skeleton of the filter element into the annular cavity of the guide fluid until the annular protrusion enters the upper skeleton of the filter element. After ensuring that the inlet sealing ring, the outlet sealing gasket, and the outlet sealing ring are in the correct positions, tighten the fastening bolts and introduce the medium. When the temperature of the temperature probes corresponding to the inlet measuring section and the outlet measuring section and the flow rate of the medium are stable, collect the pressure of the pressure probes corresponding to the inlet measuring section and the outlet measuring section, as well as the temperature and flow rate of the temperature probes. Calculate the difference between the pressures of the two pressure probes, which is the flow resistance measurement value.

[0029] Compared with the prior art, the present invention has the following characteristics:

[0030] (1) A flow resistance measurement structure was designed based on the structural characteristics of the filter element and the flow characteristics of the medium. The flow resistance measurement structure has a small volume (the volume of the guide fluid, the inlet measurement section and the outlet measurement section are small), and the structure is compact. It can accurately simulate the process of the medium flowing through the filter element. During the experimental measurement, the entire compact flow resistance measurement structure is placed in a horizontal position, which has good stability and is not easily affected by the impact of the medium flow. It is also convenient to connect with other pipelines and equipment.

[0031] (2) The addition of the diversion channel prevents the flow cross section from suddenly expanding when the medium enters the filter element from the guide fluid, which affects the accuracy of the flow resistance measurement. On the other hand, the diversion channel adopts a circular arc design, corresponding to the circumferential inlet of the filter element. Both ends of the diversion channel are round ends (semi-circular ends), which achieves the best drainage and guidance for the medium flow around the filter element.

[0032] (3) A double-seal combination structure is adopted. The axial end face of the guide fluid and the axial end face of the filter element are sealed with fluororubber gaskets, and the radial direction between the filter element and the guide fluid is sealed with a sealing ring. The combination of axial and radial sealing ensures that the medium will not directly enter the medium outlet channel from the diversion groove, achieving complete isolation of the medium inlet and outlet. On the other hand, in conjunction with the limiting cap and the guide fluid, the upper skeleton of the filter element is prevented from being deformed and damaged under the impact of the medium. That is, the probability of deformation and damage of the upper skeleton of the filter element is reduced by the support of the gasket and the sealing ring. In addition, compared with the use of a special-shaped sealing structure, the double-seal combination structure of the present invention has a lower cost and does not require customization.

[0033] (4) The quick-connect coupling is used to ensure a tight fit with the test bench nozzle connector and clamp by using a 20° bevel angle; after the sealing ring is installed in the groove of the sealing ring, a reliable seal is ensured.

[0034] (5) The temperature measuring connector is at a 45° angle to the axis of the inlet measuring section and the outlet measuring section pipe, and the direction of the angle is consistent with the direction of liquid flow, so as to ensure that the center of the temperature measuring connector coincides with the axis of the inlet measuring section and the outlet measuring section pipe. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the compact flow resistance measurement structure in this invention;

[0036] Figure 2 yes Figure 1 Schematic diagram of the AA section;

[0037] Figure 3 yes Figure 1 The left view;

[0038] Figure 4 This is a schematic diagram of the fluid guiding structure in this invention;

[0039] Figure 5 yes Figure 4 Cross-sectional view of the middle section (BB);

[0040] Figure 6 yes Figure 2 Enlarged view of region B in the middle;

[0041] Figure 7 and Figure 8 This is a schematic diagram of the temperature sensor fixing structure in this invention;

[0042] Figure 9 This is a schematic diagram of the flow direction of the medium in the compact flow resistance measurement structure of the present invention;

[0043] Figure 10 This is a schematic diagram of the quick-connect connector structure in this invention;

[0044] Figure 11 This is a schematic diagram of the structure of the annular cavity, medium inlet channel, medium outlet channel, annular protrusion and diversion groove in this invention;

[0045] Figure 12 This is a three-dimensional cross-sectional view of the flow divider in this invention;

[0046] Figure 13 This is a schematic diagram of the filter element structure to be measured in this invention;

[0047] In the diagram: 1-Inlet measuring section; 2-Inlet sealing ring; 3-Flow guide; 4-Outlet measuring section; 5-Outlet sealing gasket; 6-Outlet sealing ring; 7-Fastening bolt; 8-Limit cap; 91-Upper frame of filter element; 92-Outer shell of filter element; 93-Filter screen layer of filter element; 94-Lower frame of filter element. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0049] like Figure 13 As shown, the filter element whose flow resistance is to be measured is mainly composed of an upper filter element frame 91, a filter element outer shell 92, a filter element screen layer 93, and a lower filter element frame 94. The filter element screen layer 93 is fixed inside the filter element outer shell 92 through the upper filter element frame 91 and the lower filter element frame 94 at its axial ends. The medium flows in radially along the filter element screen layer 93 and flows out axially.

[0050] like Figures 1-6As shown, the compact flow resistance measurement structure of the present invention includes an inlet measuring section 1, an inlet sealing ring 2, a guide fluid 3, an outlet measuring section 4, an outlet sealing gasket 5, an outlet sealing ring 6, a fastening bolt 7, and a limiting cap 8. The guide fluid 3 is a rotating structure, including a media inlet channel, a media outlet channel, an annular cavity, an annular protrusion, and a diversion groove. The media inlet channel is located in a plane perpendicular to the rotation axis of the guide fluid 3, and the media outlet channel is coaxial with the rotation axis. The annular cavity is connected to both the media outlet channel and the media inlet channel, and is coaxial with the media outlet channel. The guide fluid 3 is fitted onto the filter element outer shell 92 through the annular cavity, corresponding to one end of the upper frame 91 of the filter element. The annular protrusion is located within the annular cavity, and its inner ring forms part of the media outlet channel. The annular protrusion is inserted into the upper frame 91 of the filter element. A diversion groove is provided between the outlet of the media inlet channel and the upper frame 91 of the filter element. The diversion groove is perpendicular to the rotation axis of the guide fluid 3 and extends bidirectionally from the outlet of the media inlet channel along a circumference concentric with the annular protrusion (i.e., Figure 4 (It extends bidirectionally from section BB in both clockwise and counterclockwise directions). Both ends of the expanded diversion channel are arc-shaped, and the central angle of the diversion channel is 98°.

[0051] From a force perspective, when a liquid flows in a pipe, the fluid resistance it experiences acts directly on the inner surface of the pipe wall. Perpendicular to the surface is the fluid pressure, which generates pressure resistance; parallel to the surface is frictional resistance, also known as frictional drag. This resistance manifests as fluid energy loss, and its magnitude depends on factors such as pipe length, pipe diameter, and fluid velocity.

[0052] When fluid flows in a pipe, due to the effects of fluid viscosity and eddy currents, to ensure measurement accuracy, the compact flow resistance measuring device uses the same pipe diameters for both the inlet and outlet as in the actual operating environment. When the fluid reaches the outlet of the medium inlet channel of the guide fluid 3 after passing through the inlet measuring section 1, to prevent sudden expansion (the area of ​​the annular cavity between the filter element housing 92 and the filter screen layer 93 suddenly expands), simulation calculations were performed comparing numerous models, including round ends, flat ends, and angular tips, to assess the impact of different shapes on the flow around the fluid. The results showed that the round end has the best drainage capacity. Therefore, a waist-shaped diversion channel is installed at the outlet of the medium inlet channel of the guide fluid 3 to divert the liquid. Figure 4 , Figure 11 and Figure 12 The waist-shaped diversion channel has two characteristics: the channel body is arc-shaped, and both ends of the channel body are arc-shaped. The waist-shaped diversion channel is symmetrical about the medium inlet channel of the guide fluid 3. After the liquid is diverted, it enters the filter element, is filtered by the filter screen, and flows out from the middle outlet of the filter element. The medium outlet channel of the guide fluid 3 adopts a double-sealed structure to ensure isolation between the medium inlet channel and the medium outlet channel.

[0053] like Figure 6 and Figure 9 As shown, the inlet sealing ring 2, the outlet sealing gasket 5, and the outlet sealing ring 6 constitute the sealing structure in the compact flow resistance measurement structure. The inlet sealing ring 2 is located between the inner wall of the annular cavity and the outer wall of the filter element housing 92, achieving radial sealing. The outlet sealing gasket 5 is fitted onto the outer surface of the annular protrusion, with its lower end face tightly against the upper end face of the upper frame 91 of the filter element and its upper end face tightly against the guide fluid 3, achieving end-face sealing perpendicular to the rotation axis of the guide fluid 3. The outlet sealing ring 6 is located between the upper frame 91 of the filter element and the outer surface of the annular protrusion, achieving radial sealing in a plane perpendicular to the rotation axis of the guide fluid 3. The combined sealing of the outlet sealing gasket 5 and the outlet sealing ring 6 completely isolates the medium entering the filter element from the medium flowing out of the filter element, preventing interference and thus improving the accuracy of flow resistance measurement (due to the resistance of the filter element, the double-sealing combination structure ensures that the liquid flowing in from the inlet can only flow into the filter element and then out, and will not flow directly from the inlet to the outlet, causing the test results to be distorted).

[0054] like Figure 7 and Figure 8 Temperature sensors (temperature probes) and pressure sensors (pressure probes) are installed at test points in both inlet measurement section 1 and outlet measurement section 4 to detect the temperature and pressure differences before and after measurement. The placement of the temperature and pressure sensors is related to the liquid flow direction and the position of the filter element. To minimize the combined effects of pressure resistance and friction resistance, the axis of the temperature probe forms a 45° angle with the axes of the inlet measurement section 1 and outlet measurement section 4, and its placement direction is consistent with the liquid flow direction (the horizontal component of the insertion direction is consistent with the liquid flow direction). That is, to ensure measurement accuracy, the temperature probe is designed to be located at the center of the liquid, and its rotation is consistent with the liquid flow direction, as shown in the figure. Based on the existing temperature probe length, the nozzle length is designed to be L, that is, the distance from the nozzle inlet to the central axis of the pipe is L.

[0055] The following describes the use of a compact flow resistance measurement structure. Figure 13 The method for measuring the flow resistance of the filter element is shown below:

[0056] Data collection: During the flow resistance test, the inlet flow rate and temperature of the cold and hot sides (because there are usually other tests before the flow resistance test, at this time, the temperature and pressure of the inlet measuring section 1 are relatively higher than those of the outlet measuring section 4, so the inlet measuring section 1 is called the hot side and the outlet measuring section 4 is called the cold side) are stabilized and held for 1 minute. During this period, the flow rate fluctuates within ±2% and the temperature fluctuates within ±2℃. The inlet and outlet pressure, inlet and outlet temperature and flow rate are collected.

[0057] The temperature sensor and pressure sensor installed on the inlet measuring section 1 measure the inlet temperature T1 and inlet pressure P1, and the temperature sensor and pressure gauge installed on the outlet measuring section 4 measure the outlet temperature T2 and outlet pressure P2. The difference between P2 and P1 is the flow resistance.

[0058] In the actual test environment, the filter element, along with the compact flow resistance measurement structure, is placed horizontally on the test bench. The ends of the inlet measuring section 1 and the outlet measuring section 4 of the compact flow resistance measurement structure are connected to the oil inlet and return port of the test bench, respectively, and secured with clamps. Inlet measuring section 1 and outlet measuring section 4 are connected to the temperature sensor and pressure sensor, respectively. Considering the large number of oil pipes and lines involved and their significant weight, the horizontal placement provides better stability and is less likely to affect the accuracy of the flow resistance measurement. Furthermore, during the flow resistance test, the medium flows into the filter element at a certain pressure, generating a force that pulls the filter element away from the guide fluid 3. The limiting cap 8 and the fastening bolts 7 ensure that the filter element does not separate from the guide fluid 3 and the outlet sealing gasket 5. Figure 3 One end of each of the two fastening bolts 7 is tightened onto the fluid guide 3 through the threaded hole on the mounting ear of the fluid guide 3, and the other end is connected to the threaded hole of the limiting cap 8, thereby fixing the filter element between the fluid guide 3 and the limiting cap 8. Even under the impact of the medium flow, the filter element can always maintain the correct position without shifting.

[0059] After the filter element and the guide fluid 3 are connected, a closed cavity is formed. The sealing structure ensures that the medium flowing inside will not leak to the outside. The medium flowing in from the inlet measuring section 1 passes through the filter element screen layer 93 in the closed cavity and then flows out from the outlet measuring section 4.

[0060] The flow resistance measurement structure of this invention employs a double-sealed structure to ensure that the medium does not flow directly from the inlet to the outlet without passing through the filter element. Quick-connect couplings are provided for the inlet measurement section 1 and the outlet measurement section 4 to connect to the test bench pipe. To ensure measurement accuracy, the temperature connector is at a 45° angle to the pipe axis, and the center of the measuring connector is aligned with the pipe axis.

[0061] The above description is merely one specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A compact flow resistance measurement structure for measuring the flow resistance of a filter element, wherein the filter element is mainly composed of an upper filter element skeleton (91), a filter element outer shell (92), a filter element screen layer (93), and a lower filter element skeleton (94). The filter element screen layer (93) is fixed inside the filter element outer shell (92) by the upper filter element skeleton (91) and the lower filter element skeleton (94) at its axial ends. The medium flows in radially and out axially along the filter element screen layer (93). The structure is characterized by: The compact flow resistance measurement structure includes, The guide fluid (3) is a rotating structure and includes a medium inlet channel, a medium outlet channel, an annular cavity, an annular protrusion, and a diversion groove. The medium inlet channel is located in a plane perpendicular to the rotation axis of the guide fluid (3), the medium outlet channel is coaxial with the rotation axis, and the annular cavity is connected to both the medium outlet channel and the medium inlet channel, and is coaxial with the medium outlet channel. The guide fluid (3) is fitted onto the filter element outer shell (92) through the annular cavity, corresponding to the upper frame (91) of the filter element. At one end, the annular protrusion is located in the annular cavity. The inner ring of the annular protrusion forms part of the medium outlet channel. The annular protrusion is inserted into the upper skeleton (91) of the filter element. A diversion groove is provided between the outlet of the medium inlet channel and the upper skeleton (91) of the filter element. The diversion groove is perpendicular to the rotation axis of the guide fluid (3) and extends bidirectionally from the outlet of the medium inlet channel along a circle concentric with the annular protrusion. Both ends of the expanded diversion groove are arc-shaped, and the central angle corresponding to the diversion groove is less than 180°. The inlet measuring section (1) has its first axial end coaxially connected to the inlet of the medium inlet channel; The first axial end of the outlet measuring section (4) is coaxially connected to the outlet of the medium outlet channel; An inlet sealing ring (2) is provided between the inner wall of the annular cavity and the outer wall of the filter element housing (92); The outlet sealing gasket (5) is fitted onto the outer surface of the annular protrusion, and one end face of the outlet sealing gasket (5) is in close contact with the end face of the upper skeleton (91) of the filter element, and the other end face is in close contact with the guide fluid (3), so as to achieve end face sealing perpendicular to the rotation axis of the guide fluid (3). The outlet sealing ring (6) is disposed between the upper skeleton (91) of the filter element and the outer surface of the annular protrusion to achieve radial sealing in a plane perpendicular to the rotation axis of the guide fluid (3).

2. The compact flow resistance measurement structure according to claim 1, characterized in that: The inlet sealing ring (2) and the outlet sealing ring (6) are located in the same plane, and the plane is perpendicular to the rotation axis of the guide fluid (3).

3. The compact flow resistance measurement structure according to claim 1, characterized in that: The inlet sealing ring (2) and the outlet sealing ring (6) are sealing rings with circular cross sections, and the outlet sealing gasket (5) is a sealing gasket with rectangular cross sections.

4. The compact flow resistance measurement structure according to claim 1, characterized in that: It also includes, A limiting cap (8) is placed on the filter element outer shell (92) at one end corresponding to the lower frame (94) of the filter element; Fastening bolts (7); Mounting ears, which are disposed on the fluid guide (3); The two ends of the fastening bolt (7) are connected to the mounting ear and the limiting cap (8) respectively, so that the filter element is fixed between the fluid guide (3) and the limiting cap (8).

5. The compact flow resistance measurement structure according to claim 1, characterized in that: The inlet measuring section (1), outlet measuring section (4), and guide fluid (3) are welded together.

6. The compact flow resistance measurement structure according to claim 1, characterized in that: Temperature measuring connectors are provided on both the inlet measuring section (1) and the outlet measuring section (4). The axis of the temperature measuring connector forms a 45° angle with the axis of the inlet measuring section (1) and the outlet measuring section (4). When a temperature measuring probe is inserted into the temperature measuring connector, the projection of the insertion direction of the temperature measuring probe onto the axis of the inlet measuring section (1) and the outlet measuring section (4) includes an axial component, which is opposite to the flow direction of the medium in the inlet measuring section (1) and the outlet measuring section (4).

7. The compact flow resistance measurement structure according to claim 6, characterized in that: Pressure testing connectors are provided on both the inlet measuring section (1) and the outlet measuring section (4). The axis of the pressure testing connector is perpendicular to the axis of the inlet measuring section (1) and the outlet measuring section (4), and the straight-line distance from the pressure testing connector to the guide fluid (3) is less than the straight-line distance from the temperature measuring connector to the guide fluid (3).

8. The compact flow resistance measurement structure according to claim 1, characterized in that: The inlet measuring section (1) and the outlet measuring section (4) have a conical structure on the outer side of their second axial end, and a sealing ring is provided on the large diameter end face of the conical structure.

9. The compact flow resistance measurement structure according to claim 1, characterized in that: The inner wall of the annular cavity has internal threads, and the outer surface of the filter element housing (92) has external threads, and the two are connected by threads.

10. A method for measuring the flow resistance of a filter cartridge using the compact flow resistance measurement structure described in claim 4, characterized in that: include, Adjust the placement of the guide fluid (3) so that the axes of the inlet measuring section (1), the outlet measuring section (4) and the guide fluid (3) are all parallel to the horizontal plane. Insert one end of the filter element corresponding to the upper skeleton (91) of the filter element into the annular cavity of the guide fluid (3) until the annular protrusion enters the upper skeleton (91) of the filter element. After ensuring that the inlet sealing ring (2), the outlet sealing gasket (5) and the outlet sealing ring (6) are in the correct position, tighten the fastening bolt (7) and introduce the medium. When the temperature of the temperature probe corresponding to the inlet measuring section (1) and the outlet measuring section (4) and the flow rate of the medium are stable, collect the pressure of the pressure probe corresponding to the inlet measuring section (1) and the outlet measuring section (4) and the temperature and flow rate of the temperature probe. Calculate the difference between the pressures of the two pressure probes, which is the flow resistance measurement value.

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