Liquid level detection device and water delivery system with same
By designing a protective structure of the floating body accommodating cavity and a reasonable communication port in the liquid level detection device, the problem of the liquid level switch being susceptible to blockage is solved, and accurate detection and sensitive control of the liquid level height are achieved.
Patent Information
- Application Number
- CN202422568903.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-10-23
AI Technical Summary
Existing liquid level switches are susceptible to garbage entanglement or hooks in the water collection well, resulting in inaccurate detection of liquid level height, resulting in liquid overflow or too low liquid level.
A liquid level detection device is designed, including a liquid level switch and a protective structure. The floating body is located in the receiving cavity. The switch body is detachably arranged at the opening. The protective structure is fixed in the water collection well. The communication port is designed reasonably to avoid the floating body being stuck and ensure that the floating body is subjected to uniform stress.
The accurate reaction level height of the liquid level switch is achieved, avoiding floating body blockage, ensuring the accuracy and sensitivity of liquid level detection, and making it easier to repair and replace.
Smart Images
Figure CN223140076U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of water delivery systems, and more specifically, to a liquid level detection device and a water delivery system having the same. Background Art
[0002] The liquid level switch uses the buoyancy of the liquid on the floating body and the gravity of the floating body to complete the switch control. When the floating body rises to a certain height, the switch body of the liquid level switch can be closed or opened. Therefore, the state of the switch body reflects the height of the liquid level. However, in the prior art, when the liquid level switch detects the liquid level height of the sump, it is very easy to have the situation of garbage entanglement, heavy object hooking the floating body, and the floating body getting stuck at the edge of the sump, so that the liquid level switch cannot accurately reflect the liquid level height, resulting in liquid overflowing from the sump or the liquid level in the sump being too low. Summary of the Utility Model
[0003] The utility model provides a liquid level detection device and a water delivery system having the same to solve the problem that the liquid level switch in the prior art cannot accurately reflect the liquid level height.
[0004] According to one aspect of the utility model, a liquid level detection device is provided. The liquid level detection device includes: a liquid level switch having a floating body and a switch body, the floating body being drivingly connected to the switch body to control the opening and closing of the switch body; a protection structure having a receiving cavity, an opening, and a plurality of communication ports, the opening and the plurality of communication ports being in communication with the receiving cavity, the plurality of communication ports being spaced apart along the extending direction of the protection structure, the protection structure being for fixing in the sump, the plurality of communication ports being for communicating the receiving cavity and the sump, the floating body being floatingly disposed in the receiving cavity, and the switch body being detachably disposed at the opening.
[0005] Further, the top of the protection structure is provided with an opening, and the bottom of the protection structure is provided with a plurality of first communication ports.
[0006] Further, the bottom of the protection structure is provided with 4 to 5 first communication ports, and the diameter of the first communication ports is set between 5 mm and 10 mm.
[0007] Further, a plurality of second communication ports, a plurality of third communication ports, and a plurality of fourth communication ports are provided on the side wall of the protection structure, the plurality of second communication ports, the plurality of third communication ports, and the plurality of fourth communication ports are axially spaced along the protection structure, the plurality of second communication ports are circumferentially and annularly spaced along the protection structure, the plurality of third communication ports are circumferentially and annularly spaced along the protection structure, and the plurality of fourth communication ports are circumferentially and annularly spaced along the protection structure.
[0008] Further, the distance between the second communication port and the bottom end of the protection structure is set between 20 mm and 60 mm; the distance between the third communication port and the bottom end of the protection structure is set between 600 mm and 900 mm; the distance between the fourth communication port and the opening of the protection structure is set between 150 mm and 200 mm.
[0009] Further, the height of the protection structure is set between 1 m and 1.8 m.
[0010] Further, the liquid level detection device further includes: a locking structure disposed at the opening to fix the switch body at the opening; a fixing structure for being disposed in the catch basin, and the fixing structure is used to support the protection structure.
[0011] Further, the switch body has a housing with a first end and a second end disposed opposite to each other. The diameter of the first end of the housing gradually decreases in a direction away from the second end. The first end of the housing is disposed in the opening, and the second end of the housing is located outside the protection structure. The locking structure is a snap structure.
[0012] Further, the fixing structure includes: a fixing portion, one end of the fixing portion is used to be fixed in the catch basin; a first clamping portion and a second clamping portion, one end of the first clamping portion and one end of the second clamping portion are both hinged to the other end of the fixing portion, the other end of the first clamping portion and the other end of the second clamping portion are detachably connected, and the first clamping portion and the second clamping portion cooperate to fix the protection structure.
[0013] Further, the protection structure is made of stainless steel or PVC material.
[0014] According to another aspect of the present invention, there is provided a water delivery system, which includes a water delivery pipe, a control valve, a catch basin, a control system, and the liquid level detection device provided above. A control valve is provided on the water delivery pipe, the outlet of the water delivery pipe corresponds to the catch basin, the protection structure of the liquid level detection device is fixed in the catch basin, the control system is electrically connected to the liquid level switch and the control valve of the liquid level detection device, the liquid level switch can transmit a signal to the control system, and the control system can control the opening and closing of the control valve according to the signal of the liquid level switch.
[0015] Applying the technical solution of the present utility model, the floating body is located in the accommodation cavity, the switch body is located at the opening of the protection structure, and the communication port can communicate the sump and the accommodation cavity, so that the liquid can flow into the accommodation cavity, ensuring that the floating body can receive the same buoyancy as outside the accommodation cavity. With such a setting, since the floating body is located in the accommodation cavity, it can avoid garbage entanglement or heavy object hooking on the floating body. Since the protection structure is fixed in the sump, when there is a large amount of incoming water, it can prevent the floating body from getting stuck at the edge of the sump, so that the liquid level switch can accurately reflect the liquid level height, avoiding the liquid level in the sump being too high or too low, thus ensuring the subsequent normal production work. And because the switch body is detachably arranged at the opening, it is convenient to disassemble and install the liquid level switch, thus facilitating the maintenance and replacement of the liquid level switch by the staff. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:
[0017] Figure 1 The structural schematic diagram of the liquid level switch provided by the present utility model is shown;
[0018] Figure 2 The structural schematic diagram of the protection structure provided by the present utility model is shown;
[0019] Figure 3 The bottom view of the protection structure provided by the present utility model is shown.
[0020] Among them, the above-mentioned accompanying drawings include the following reference numerals:
[0021] 10. Liquid level switch;
[0022] 11. Floating body;
[0023] 12. Switch body;
[0024] 13. Connecting wire;
[0025] 20. Protection structure;
[0026] 21. Opening;
[0027] 22. First communication port;
[0028] 23. Second communication port;
[0029] 24. Third communication port;
[0030] 25. Fourth communication port. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present utility model and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.
[0032] As Figures 1 to 3 shown, the embodiment of the present utility model provides a liquid level detection device, which includes a liquid level switch 10 and a protection structure 20. The liquid level switch 10 has a floating body 11 and a switch body 12. The floating body 11 is drivingly connected to the switch body 12, and the floating body 11 controls the opening and closing of the switch body 12. The protection structure 20 has a receiving cavity, an opening 21, and a plurality of communication ports. The opening 21 and the plurality of communication ports are both communicated with the receiving cavity. The plurality of communication ports are arranged at intervals along the extending direction of the protection structure 20. The protection structure 20 is used to be fixed in the sump, and the plurality of communication ports are used to communicate the receiving cavity and the sump. The floating body 11 is floatingly arranged in the receiving cavity, and the switch body 12 is detachably arranged at the opening 21. Among them, in this application, the opening 21 of the protection structure 20 is located above the water surface, that is, the switch body 12 is located above the water surface.
[0033] Applying the technical solution of this application, the floating body 11 is located in the receiving cavity, the switch body 12 is located at the opening 21 of the protection structure 20, and the communication ports can communicate the sump and the receiving cavity, so that the liquid can flow into the receiving cavity, ensuring that the floating body 11 can receive the same buoyancy as outside the receiving cavity. With this setting, since the floating body 11 is located in the receiving cavity, it can avoid garbage entanglement or heavy object hook on the floating body 11. Since the protection structure 20 is fixed in the sump, when a large amount of water comes, it can prevent the floating body 11 from getting stuck at the edge of the sump, so that the liquid level switch 10 can accurately reflect the liquid level height, avoid the liquid level in the sump being too high or too low, and thus ensure the subsequent normal production work. And because the switch body 12 is detachably arranged at the opening 21, it is convenient to disassemble and install the liquid level switch 10, so as to facilitate the maintenance and replacement of the liquid level switch 10 by the staff.
[0034] Among them, as Figure 1 shown, the liquid level switch 10 has two floating bodies 11. The tail of one floating body 11 is connected to the head of the other floating body 11, and the head of this floating body 11 is connected to the switch body 12 through a connecting wire 13. With this setting, the weights of the two floating bodies 11 are relatively heavy, which can improve the sensitivity of the liquid level switch 10 and ensure that when the liquid level is too low, the switch body 12 is in the open state, and when the liquid level is too high, the switch body 12 is in the closed state.
[0035] As Figure 2 and Figure 3 shown, an opening 21 is provided at the top of the protection structure 20, and a plurality of first communication ports 22 are provided at the bottom of the protection structure 20. With such a setting, it is convenient to process the protection structure 20, and at the same time, it can ensure that the liquid smoothly enters the accommodation cavity, ensuring that the floating body 11 can normally receive buoyancy.
[0036] Specifically, 4 to 5 first communication ports 22 are provided at the bottom of the protection structure 20. With such a setting, it can ensure the smoothness of the liquid flowing into the accommodation cavity, thereby ensuring the buoyancy of the liquid on the floating body 11.
[0037] Optionally, the diameter of the protection structure 20 is designed to be 60 mm, and a plurality of first communication ports 22 are evenly distributed at the bottom of the protection structure 20.
[0038] The diameter of the first communication port 22 is set between 5 mm and 10 mm. With such a setting, when the diameter of the first communication port 22 is less than 5 mm, the diameter of the first communication port 22 is too small, and the speed of the liquid entering the accommodation cavity through the first communication port 22 is slow, thereby reducing the sensitivity of the liquid level switch 10. When the diameter of the first communication port 22 is greater than 10 mm, the diameter of the first communication port 22 is too large, and impurities can easily enter the accommodation cavity through the first communication port 22, thereby easily affecting the accuracy of the liquid level switch 10 in reflecting the liquid level height. Therefore, setting the diameter of the first communication port 22 between 5 mm and 10 mm can ensure that the liquid can flow smoothly into the accommodation cavity, and at the same time, it can prevent impurities in the sump from entering the accommodation cavity, thereby ensuring the sensitivity and accuracy of the liquid level switch 10.
[0039] Optionally, the diameter of the first communication port 22 is set to 5 mm, 8 mm or 10 mm. In this application, the diameter of the first communication port 22 is 10 mm.
[0040] Further, a plurality of second communication ports 23, a plurality of third communication ports 24 and a plurality of fourth communication ports 25 are provided on the side wall of the protection structure 20. The plurality of second communication ports 23, the plurality of third communication ports 24 and the plurality of fourth communication ports 25 are arranged at intervals along the axial direction of the protection structure 20. The plurality of second communication ports 23 are arranged at circumferential intervals along the protection structure 20. The plurality of third communication ports 24 are arranged at circumferential intervals along the protection structure 20. The plurality of fourth communication ports 25 are arranged at circumferential intervals along the protection structure 20. With the above structure, it can be ensured that at least one of the second communication port 23, the third communication port 24 and the fourth communication port 25 is located below the water surface, and at least one is located above the water surface. With such a setting, it can ensure that the pressure in the accommodation cavity is the atmospheric pressure, and at the same time, it can ensure that the liquid can flow into the accommodation cavity in sequence.
[0041] Optionally, in the present application, some of the second communication ports 23 are distributed at intervals along the axial direction of the protection structure 20, and the distance between two adjacent second communication ports 23 distributed along the axial direction is set to 50 mm; some of the third communication ports 24 are distributed at intervals along the axial direction of the protection structure 20, and the distance between two adjacent third communication ports 24 distributed along the axial direction is set to 50 mm; some of the fourth communication ports 25 are distributed at intervals along the axial direction of the protection structure 20, and the distance between two adjacent fourth communication ports 25 distributed along the axial direction is set to 50 mm.
[0042] Among them, the distance between the second communication port 23 and the bottom end of the protection structure 20 is set between 20 mm and 60 mm. With such a setting, it can ensure that the liquid in the sump enters the accommodation cavity through the second communication port 23, which can improve the liquid flow rate. Moreover, when the first communication port 22 is blocked, the liquid can still enter the accommodation cavity through the second communication port 23, so as to ensure that the liquid level in the accommodation cavity is the same as that outside the accommodation cavity.
[0043] Specifically, the distance between the third communication port 24 and the bottom end of the protection structure 20 is set between 600 mm and 900 mm, and the distance between the fourth communication port 25 and the opening 21 of the protection structure 20 is set between 150 mm and 200 mm.
[0044] With such a setting, when the height of the protection structure 20 is small, the third communication port 24 is above the water surface, and air can enter the accommodation cavity through the third communication port 24, so as to balance the internal and external pressures of the protection structure 20 and ensure that the floating body 11 can float normally. The fourth communication port 25 is below the water surface, and the liquid can also flow into the accommodation cavity through the fourth communication port 25, further improving the speed of the fluid entering the accommodation cavity, and thus further improving the sensitivity of the liquid level switch 10.
[0045] When the protection structure 20 is relatively high, the third communication port 24 is below the water surface, and the liquid can also flow into the accommodation cavity through the third communication port 24, further improving the speed of the fluid entering the accommodation cavity, and thus further improving the sensitivity of the liquid level switch 10. The fourth communication port 25 is above the water surface, and air can enter the accommodation cavity through the fourth communication port 25, so as to balance the internal and external pressures of the protection structure 20 and ensure that the floating body 11 can float normally.
[0046] Optionally, in other cases, both the third communication port 24 and the fourth communication port 25 are above the water surface or both are below the water surface.
[0047] Furthermore, the height of the protection structure 20 is set between 1 m and 1.8 m. With such a setting, when the height of the protection structure 20 is less than 1 m, the applicability of the protection structure 20 is relatively low. During the water filling process of the sump, the water surface is very likely to overflow the top of the protection structure 20, resulting in easy damage to the liquid level switch 10. When the height of the protection structure 20 is greater than 1.8 m, the protection structure 20 is too high, which will increase the production cost of the protection structure 20 and cause waste of resources. Therefore, setting the height of the protection structure 20 between 1 m and 1.8 m can not only improve the applicability of the protection structure 20 but also reduce the production cost of the protection structure 20 and avoid waste of resources.
[0048] Optionally, the height of the protection structure 20 can be 1 m, 1.5 m, or 1.8 m. In this application, the height of the protection structure 20 is 1.5 m.
[0049] Among them, the liquid level detection device further includes a locking structure and a fixing structure. The locking structure is arranged at the opening 21 to fix the switch body 12 at the opening 21. With such a setting, it can be avoided that the switch body 12 falls from the opening 21, ensuring the normal operation of the liquid level switch 10. The fixing structure is used to be arranged in the sump, and the fixing structure is used to support the protection structure 20. With such a setting, it can be avoided that the protection structure 20 is inclined or toppled, thus ensuring the normal operation of the liquid level switch 10.
[0050] Specifically, the switch body 12 has a housing, the housing has a first end and a second end arranged oppositely, the diameter of the first end of the housing gradually decreases in the direction away from the second end, the first end of the housing is arranged in the opening 21, the second end of the housing is located outside the protection structure 20, and the locking structure is a snap structure. With such a setting, it is convenient to fix the liquid level switch 10 at the opening 21. At the same time, the locking structure is simple in structure and convenient to fix the liquid level switch 10.
[0051] Optionally, the first end of the housing has a connecting portion, the diameter of the connecting portion gradually decreases in the direction away from the second end of the housing, the diameter of the connecting portion is smaller than the diameter of the second end of the housing, and there is a stepped surface between the connecting portion and the second end of the housing.
[0052] Furthermore, the fixing structure includes a fixing portion, a first clamping portion, and a second clamping portion. One end of the fixing portion is used to be fixed in the sump. One end of the first clamping portion and one end of the second clamping portion are both hinged to the other end of the fixing portion, the other end of the first clamping portion and the other end of the second clamping portion are detachably connected, and the first clamping portion and the second clamping portion cooperate to fix the protection structure 20. With such a setting, it is convenient for the fixing structure to fix the protection structure 20, and the fixing structure is simple in structure and convenient to assemble.
[0053] Among them, the protection structure 20 is made of stainless steel or PVC. With this arrangement, it is possible to prevent the protection structure 20 from rusting or being corroded, improve the service life of the protection structure 20, and avoid repeatedly replacing the protection structure 20.
[0054] Another embodiment of the present utility model provides a water conveyance system, which includes a water conveyance pipe, a control valve, a sump, a control system, and the above-provided liquid level detection device. A control valve is provided on the water conveyance pipe, and the outlet of the water conveyance pipe is correspondingly arranged opposite to the sump. The protection structure 20 of the liquid level detection device is fixed in the sump. The control system is electrically connected to the liquid level switch 10 and the control valve of the liquid level detection device. The liquid level switch 10 can transmit a signal to the control system, and the control system can control the opening and closing of the control valve according to the signal of the liquid level switch 10. With this arrangement, the protection structure 20 can protect the liquid level switch 10, and can prevent garbage from entangling or heavy objects from hooking the floating body 11 of the liquid level switch 10, thereby improving the accuracy of the liquid level switch 10, accurately controlling the water conveyance work of the water conveyance pipe, and avoiding the liquid level in the sump from being too high or too low.
[0055] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0056] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present utility model. At the same time, it should be understood that for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.
[0057] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present utility model; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.
[0058] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper...", etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation other than the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.
[0059] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without additional statement, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present utility model.
[0060] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A liquid level detection device, characterized in that, The liquid level detection device includes: A liquid level switch (10), the liquid level switch (10) having a floating body (11) and a switch body (12), the floating body (11) being drivingly connected to the switch body (12), and the floating body (11) controlling the opening and closing of the switch body (12); A protection structure (20), the protection structure (20) having a receiving cavity, an opening (21), and a plurality of communication ports, the opening (21) and the plurality of communication ports being in communication with the receiving cavity, the plurality of communication ports being spaced apart along the extending direction of the protection structure (20), the protection structure (20) being for fixing in a sump, the plurality of communication ports being for communicating the receiving cavity and the sump, the floating body (11) being floatingly disposed in the receiving cavity, and the switch body (12) being detachably disposed at the opening (21).
2. The liquid level detection device according to claim 1, wherein The opening (21) is provided at the top of the protection structure (20), and a plurality of first communication ports (22) are provided at the bottom of the protection structure (20).
3. The liquid level detection device according to claim 2, wherein, 4 to 5 of the first communication ports (22) are provided at the bottom of the protection structure (20), and the diameter of the first communication ports (22) is set between 5 mm and 10 mm.
4. The liquid level detection device according to claim 1, characterized in that, A plurality of second communication ports (23), a plurality of third communication ports (24), and a plurality of fourth communication ports (25) are provided on the side wall of the protection structure (20), the plurality of second communication ports (23), the plurality of third communication ports (24), and the plurality of fourth communication ports (25) being axially spaced along the protection structure (20), the plurality of second communication ports (23) being circumferentially and annularly spaced along the protection structure (20), the plurality of third communication ports (24) being circumferentially and annularly spaced along the protection structure (20), and the plurality of fourth communication ports (25) being circumferentially and annularly spaced along the protection structure (20).
5. The liquid level detection device according to claim 4, wherein The distance between the second communication port (23) and the bottom end of the protection structure (20) is set between 20 mm and 60 mm; The distance between the third communication port (24) and the bottom end of the protection structure (20) is set between 600 mm and 900 mm; The distance between the fourth communication port (25) and the opening (21) of the protection structure (20) is set between 150 mm and 200 mm.
6. The liquid level detection device according to claim 1, characterized in that The height of the protection structure (20) is set between 1 m and 1.8 m.
7. The liquid level detection device according to claim 1, wherein, The liquid level detection device further includes: A locking structure provided at the opening (21) to fix the switch body (12) at the opening (21); A fixing structure for being disposed in the sump, the fixing structure being for supporting the protection structure (20).
8. The liquid level detection device according to claim 7, characterized in that, The switch body (12) has a housing, the housing has a first end and a second end arranged oppositely, the diameter of the first end of the housing gradually decreases in a direction away from the second end, the first end of the housing is arranged in the opening (21), the second end of the housing is located outside the protection structure (20), and the locking structure is a snap structure.
9. The liquid level detection device according to claim 7, characterized in that, The fixing structure includes: A fixing part, one end of the fixing part is used for being fixed in the sump well; A first clamping part and a second clamping part, one ends of the first clamping part and the second clamping part are both hinged to the other end of the fixing part, the other ends of the first clamping part and the second clamping part are detachably connected, and the first clamping part and the second clamping part cooperate to fix the protection structure (20).
10. The liquid level detection device according to claim 1, wherein, The protection structure (20) is made of stainless steel or PVC material.
11. A water delivery system, characterized in that, The water delivery system includes a water delivery pipe, a control valve, a sump well, a control system and the liquid level detection device according to any one of claims 1 to 10. The control valve is arranged on the water delivery pipe, the outlet of the water delivery pipe corresponds to the sump well, the protection structure (20) of the liquid level detection device is fixed in the sump well, the control system is electrically connected to the liquid level switch (10) and the control valve of the liquid level detection device, the liquid level switch (10) can transmit a signal to the control system, and the control system can control the opening and closing of the control valve according to the signal of the liquid level switch (10).