Water purification system and control method thereof

Abstract

The invention relates to the technical field of water purification devices, and particularly provides a water purification system and a control method of the water purification system. The water purification system comprises a booster pump and a reverse osmosis filter element which are sequentially communicated, wherein a front filter element is arranged on a first pipeline communicated with an inlet of the booster pump, and / or a rear filter element is arranged on a second pipeline communicated with a pure water opening of the reverse osmosis filter element; the water purification system further comprises a pressure relief pipeline, a pressure relief valve is arranged on the pressure relief pipeline, the first pipeline and the second pipeline are respectively communicated with the pressure relief pipeline, or the front filter element and the rear filter element are respectively communicated with the pressure relief pipeline. The control method of the water purification system comprises the following steps: judging whether the water purification system receives a filter element replacement instruction or not; and selectively opening the pressure release valve according to the filter element replacement instruction. Water pressure in the front filter element or the rear filter element is reduced by opening the pressure release valve, the situation that the one-way valve is pushed out and fails when the filter element is replaced due to excessive water pressure in the filter element is avoided, the use safety of the filter element is improved, and the service life of the filter element is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of water purification devices, and specifically provides a water purification system and a control method for the water purification system. Background Art

[0002] Existing reverse osmosis water purifiers usually include a pre-filter element, a post-filter element, a reverse osmosis filter element and a booster pump.

[0003] Usually, a one-way valve is installed in the water outlet of the filter element. Generally speaking, after the filter element is pulled out from the water purifier, the one-way valve can block the water outlet of the filter element to prevent the water in the filter element from flowing out when replacing it. However, after the filter element is directly pulled out and replaced, the one-way valve in the filter element may suddenly pop out due to the pressure inside the filter element, causing the filter element to leak and be difficult to reset, resulting in damage to the filter element, economic losses and complaints from users, and poor user experience.

[0004] Accordingly, the art needs a new water purification system to solve the above problems. Summary of the invention

[0005] In order to solve the above problems in the prior art, that is, to solve the problem that the filter element of the existing water purifier is easily damaged due to pressure buildup in the filter element.

[0006] In a first aspect, the present invention provides a water purification system, which includes a booster pump and a reverse osmosis filter element connected in sequence, a pre-filter element is provided on a first pipeline connected to the inlet of the booster pump and / or a post-filter element is provided on a second pipeline connected to the pure water outlet of the reverse osmosis filter element; wherein, the water purification system also includes a pressure relief pipeline, a pressure relief valve is provided on the pressure relief pipeline, the first pipeline and the second pipeline are respectively connected to the pressure relief pipeline or the pre-filter element and the post-filter element are respectively connected to the pressure relief pipeline.

[0007] In the case of the preferred technical solution of the above-mentioned water purification system, a first pressure relief port is provided on the pre-filter element, and the first pressure relief port is communicated with the pressure relief pipeline.

[0008] In the case of the preferred technical solution of the above-mentioned water purification system, a second pressure relief port is provided on the post-filter element, and the second pressure relief port is connected to the pressure relief pipeline.

[0009] In the case of the preferred technical solution of the above-mentioned water purification system, the water purification system also includes a third pipeline connected to the waste water outlet of the reverse osmosis filter element, a waste water solenoid valve is provided on the third pipeline, and the pressure relief pipeline is also connected to the third pipeline.

[0010] In a second aspect, the present invention further provides a control method for the water purification system, the control method comprising: determining whether the water purification system has received a filter element replacement instruction; and selectively opening the pressure relief valve according to the filter element replacement instruction.

[0011] In the case of the preferred technical solution of the control method of the above-mentioned water purification system, the step of "selectively opening the pressure relief valve according to the filter element replacement instruction" specifically includes: if the result of the filter element replacement instruction is "yes", obtaining the operating status of the boost pump; according to the operating status of the boost pump, selectively opening the pressure relief valve.

[0012] In the case of the preferred technical solution of the control method of the water purification system mentioned above, the step of "selectively opening the pressure relief valve according to the working state of the boost pump" specifically includes: if the boost pump is in a shutdown state, opening the pressure relief valve.

[0013] In the case of the preferred technical solution of the control method of the water purification system mentioned above, the step of "selectively opening the pressure relief valve according to the operating state of the boost pump" specifically includes: if the boost pump is in operation, closing the boost pump and opening the pressure relief valve.

[0014] In the case of the preferred technical solution of the control method of the water purification system described above, the control method further comprises: opening the wastewater solenoid valve.

[0015] In the case of the preferred technical solution of the control method of the above-mentioned water purification system, the control method further includes: after the pressure relief valve is opened and maintained for a preset time, the pressure relief valve is closed and the water purification system issues a prompt message allowing the filter element to be replaced.

[0016] Those skilled in the art can understand that the water purification system of the present invention includes a booster pump and a reverse osmosis filter element connected in sequence, a pre-filter element is provided on the first pipeline connected to the inlet of the booster pump and / or a post-filter element is provided on the second pipeline connected to the pure water outlet of the reverse osmosis filter element; wherein, the water purification system also includes a pressure relief pipeline, a pressure relief valve is provided on the pressure relief pipeline, the first pipeline and the second pipeline are respectively connected to the pressure relief pipeline or the pre-filter element and the post-filter element are respectively connected to the pressure relief pipeline. The control method of the water purification system of the present invention includes: determining whether the water purification system has received an instruction to replace the filter element; selectively opening the pressure relief valve according to the instruction to replace the filter element. By opening the pressure relief valve to reduce the water pressure in the pre-filter element or the post-filter element, it is avoided that the one-way valve is pushed out and fails due to excessive water pressure inside the filter element when replacing the filter element, thereby improving the safety and life of the filter element. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0018] Figure 1 Schematic diagram of the water circuit structure of the first embodiment of the water purification system of the present invention;

[0019] Figure 2 Schematic diagram of the water circuit structure of the second embodiment of the water purification system of the present invention;

[0020] Figure 3 It is a flow chart of the main steps of the control method of the water purification system of the present invention;

[0021] Figure 4 It is a detailed step flow chart of the control method of the water purification system of the present invention.

[0022] List of reference numerals:

[0023] 1. Pre-filter element; 2. Reverse osmosis filter element; 3. Post-filter element; 4. Booster pump; 5. Faucet; 61. Water inlet solenoid valve; 62. High-pressure switch; 63. Wastewater solenoid valve; 71. First pressure relief valve; 72. Second pressure relief valve; 81. First pressure relief pipeline; 82. Second pressure relief pipeline; 83. Third pipeline. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0025] It should be noted that, in the description of the present invention, terms such as "upper", "lower", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0026] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0027] Specifically, Figure 1 to Figure 2As shown, the water purification system of the present invention comprises a pre-filter element 1, a booster pump 4, a reverse osmosis filter element 2, a post-filter element 3 and a faucet 5 which are connected in sequence. The inlet of the pre-filter element 1 is connected to the water source, the outlet of the pre-filter element 1 is connected to the inlet of the booster pump 4, the outlet of the booster pump 4 is connected to the raw water inlet of the reverse osmosis filter element 2, the pure water inlet of the reverse osmosis filter element 2 is connected to the inlet of the post-filter element 3, and the outlet of the post-filter element 3 is connected to the faucet 5.

[0028] Among them, a first pipeline is provided between the outlet of the pre-filter element 1 and the inlet of the booster pump 4, and a second pipeline is provided between the outlet of the post-filter element 3 and the faucet 5. A water inlet solenoid valve 61 is provided on the pipeline where the inlet of the pre-filter element 1 is connected to the water source, and a high-pressure switch 62 is provided on the second pipeline. The water purification system also includes a third pipeline 83 connected to the wastewater outlet of the reverse osmosis filter element 2, and a wastewater solenoid valve 63 is provided on the third pipeline 83. The water purification system also includes a pressure relief pipeline, and a pressure relief valve is provided on the pressure relief pipeline.

[0029] It should be noted that one-way valves (not shown in the figure) are provided in the water inlets and outlets of the pre-filter element 1 , the post-filter element 3 and the reverse osmosis filter element 2 .

[0030] In a preferred embodiment, Figure 1 As shown, the first pipeline and the second pipeline of the water purification system of the present invention are respectively connected to the pressure relief pipeline.

[0031] For example, Figure 1 As shown, the pressure relief pipeline of the water purification system of the present invention includes a first pressure relief pipeline 81, a first pressure relief valve 71 arranged on the first pressure relief pipeline 81, a second pressure relief pipeline 82, and a second pressure relief valve 72 arranged on the second pressure relief pipeline 82. Among them, one end of the first pressure relief pipeline 81 is connected to the first pipeline, and the other end of the first pressure relief pipeline 81 is connected to the third pipeline 83; one end of the second pressure relief pipeline 82 is connected to the second pipeline, and the other end of the second pressure relief pipeline 82 is connected to the third pipeline 83.

[0032] When the pre-filter element 1 of the water purification system needs to be replaced, the first pressure relief valve 71 is opened, and the water pressure in the pre-filter element 1 is released by means of the outlet of the pre-filter element 1, the first pipeline and the first pressure relief pipeline 81, and the water outlet in the pre-filter element 1 after pressure relief flows into the third pipeline 63 and is discharged together with the concentrated water flowing out of the wastewater outlet of the reverse osmosis filter element 2.

[0033] When the post-filter element 3 of the water purification system needs to be replaced, the second pressure relief valve 72 is opened, and the water pressure in the post-filter element 3 is released by means of the outlet of the post-filter element 3, the second pipeline and the second pressure relief pipeline 82, and the outlet water in the post-filter element 3 after pressure relief flows into the third pipeline 63 and is discharged together with the concentrated water flowing out of the wastewater outlet of the reverse osmosis filter element 2.

[0034] That is to say, the first pressure relief line 81 directly relieves the pressure of the first pipeline, which indirectly reduces the pressure of the water in the pre-filter element 1. The second pressure relief line 82 directly relieves the pressure of the second pipeline, which indirectly reduces the pressure of the water in the post-filter element 3. Therefore, when the pre-filter element 1 or the post-filter element 3 is replaced after the pressure is relieved, the one-way valve on the pre-filter element 1 or the post-filter element 3 will not leak due to the water pressure in the filter element, thereby improving the safety and life of the filter element.

[0035] In another preferred embodiment, Figure 2 As shown, the pre-filter element 1 and the post-filter element 3 of the water purification system of the present invention are respectively connected to the pressure relief pipeline.

[0036] For example, Figure 2 As shown, the pressure relief pipeline of the water purification system of the present invention includes a first pressure relief pipeline 81, a first pressure relief valve 71 arranged on the first pressure relief pipeline 81, a second pressure relief pipeline 82, and a second pressure relief valve 72 arranged on the second pressure relief pipeline 82. Among them, the pre-filter element 1 is also provided with a first pressure relief port, the first pressure relief port is connected to one end of the first pressure relief pipeline 81, and the other end of the first pressure relief pipeline 81 is connected to the third pipeline 83. The post-filter element 3 is also provided with a second pressure relief port, the second pressure relief port is connected to one end of the second pressure relief pipeline 82, and the other end of the second pressure relief pipeline 82 is connected to the third pipeline 83.

[0037] It should be noted that both the first pressure relief port of the pre-filter element 1 and the second pressure relief port of the post-filter element 3 are provided with a one-way valve.

[0038] When the pre-filter element 1 of the water purification system needs to be replaced, the first pressure relief valve 71 is opened, and the water pressure in the pre-filter element 1 is released by means of the first pressure relief port of the pre-filter element 1 and the first pressure relief pipeline 81, and the water outlet in the pre-filter element 1 after pressure relief flows into the third pipeline 63 and is discharged together with the concentrated water flowing out of the wastewater outlet of the reverse osmosis filter element 2.

[0039] When the post-filter element 3 of the water purification system needs to be replaced, the second pressure relief valve 72 is opened, and the water pressure in the post-filter element 3 is released by means of the second pressure relief port and the second pressure relief pipeline 82 of the post-filter element 3, and the water outlet in the post-filter element 3 after pressure relief flows into the third pipeline 63 and is integrated and discharged together with the concentrated water flowing out of the wastewater outlet of the reverse osmosis filter element 2.

[0040] It should be noted that, in the above two preferred methods, the preferred setting method is that the pre-filter element 1 and the post-filter element 3 are respectively connected to the pressure relief pipeline. The water purification system directly releases the water pressure in the pre-filter element 1 and the post-filter element 3 through the first pressure relief port of the pre-filter element 1 and the first pressure relief pipeline 81 and the second pressure relief port of the post-filter element 3 and the second pressure relief pipeline 82. The pressure relief efficiency is high and the speed is fast, which facilitates the rapid replacement of the filter element in the water purification system.

[0041] In addition, it should be noted that the water purification system of the present invention also includes a controller (not shown in the figure).

[0042] Specifically, the booster pump 4, wastewater solenoid valve 63, high-pressure switch 62, water inlet solenoid valve 61, first pressure relief valve 71 and second pressure relief valve 72 of the water purification system of the present invention are all communicatively connected to the controller so that the controller can communicate and control the above components when receiving the filter element update command signal.

[0043] like Figure 3 As shown, the control method of the water purification system of the present invention mainly includes the following main steps:

[0044] S1, determining whether the water purification system has received a filter element replacement instruction;

[0045] S2. Selectively open the pressure relief valve according to the filter element replacement instruction.

[0046] Specifically, the water purification system of the present invention further includes a filter cartridge replacement button module (not shown in the figure) that is communicatively connected to the controller.

[0047] When the button module is pressed and triggered by the user, the controller receives the instruction information of the filter element replacement button module. According to the received instruction information, the controller controls the opening of the pressure relief valve to release the pressure in the filter element.

[0048] Exemplarily, the filter element replacement button module includes a first button for replacing the pre-filter element 1 (not shown in the figure) and a second button for replacing the post-filter element 3 (not shown in the figure).

[0049] When the pre-filter element 1 expires and needs to be replaced, the user presses the first button. The controller of the water purification system receives the instruction information of the first button and controls the opening of the first pressure relief valve 71 to relieve the pressure of the pre-filter element 1 according to the instruction information.

[0050] When the post filter 3 expires and needs to be replaced, the user presses the first button. The controller of the water purification system receives the command information of the first button, and controls the second pressure relief valve 72 to release the pressure of the post filter 3 according to the command information.

[0051] It should be noted that, according to actual applications, those skilled in the art may also only set one filter element replacement button. When the service life of either the pre-filter element 1 or the post-filter element 3 expires and needs to be replaced, the controller of the water purification system receives the instruction information of the filter element replacement button and simultaneously opens the first pressure relief valve 71 and the second pressure relief valve 72. Such adjustments and changes to the specific presentation form of the filter element replacement button module do not deviate from the principle and scope of the present invention and should be limited within the protection scope of the present invention.

[0052] Of course, it is preferred to set the filter element replacement button module to include a first button for replacing the front filter element 1 and a second button for replacing the rear filter element 3. In this way, it is more convenient for users to select the filter element for pressure relief replacement.

[0053] like Figure 4 As shown, the detailed steps of the control method of the water purification system of the present invention are as follows

[0054] S1, determining whether the water purification system has received a filter element replacement instruction;

[0055] S21, if the result of the filter element replacement instruction is "yes";

[0056] S22, obtaining the working state of the booster pump 4;

[0057] S231, if the booster pump 4 is in a shutdown state, open the pressure relief valve;

[0058] S232: If the booster pump 4 is in operation, turn off the booster pump 4 and open the pressure relief valve.

[0059] For example, if the user does not press the filter cartridge replacement button, the water purification system does not receive the filter cartridge replacement instruction. At this time, the water purification system maintains a normal operating state.

[0060] When the user needs to replace the filter element of the water purification system, the user presses the filter element replacement button to generate a filter element replacement instruction. When the controller receives the filter element replacement instruction and the result is "yes", it is necessary to determine the current working state of the water purification system.

[0061] That is, the two current operating states of the water purification system when the filter element is replaced are confirmed by acquiring the operating state of the boost pump 4 .

[0062] In the first working condition, if the booster pump 4 of the water purification system is in a shutdown state, it indicates that the water purification system is in a standby state. That is, the water inlet solenoid valve 61 and the booster pump 4 of the water purification system are both in a closed state. At this time, after receiving the filter element replacement instruction, the controller only needs to open the pressure relief valve to directly release the pressure.

[0063] In the second working condition, if the booster pump 4 of the water purification system is in operation, it indicates that the water purification system is in the working state of water production. That is, the water inlet solenoid valve 61 and the booster pump 4 of the water purification system are both in the open state. At this time, after the controller receives the filter element replacement instruction, the controller needs to first close the booster pump 4 and the water inlet solenoid valve 61, and then open the pressure relief valve to release the pressure.

[0064] Preferably, the control method of the present invention further comprises: after the pressure relief valve is opened for a preset time, the pressure relief valve is closed and the water purification system issues a prompt message allowing the filter element to be replaced.

[0065] Exemplarily, the water purification system of the present invention further comprises a prompt screen in communication with the controller. After the pressure relief valve is opened and maintained for 15 seconds (preset time), the pressure relief valve is closed.

[0066] The controller of the water purification system controls the prompt screen to display the prompt message "Please replace the filter element" to remind the user to pull out the filter element for replacement.

[0067] It should be noted that, according to actual applications, technical personnel in this field may choose to use an indicator light to present prompt information, and remind the user to pull out the filter element according to the color of the indicator light, or may choose to use a language module to present prompt information, and remind the user to pull out the filter element through language. Such adjustments and changes to the specific presentation form of the prompt information do not deviate from the principle and scope of the present invention, and should be limited within the protection scope of the present invention.

[0068] In addition, it should be noted that the selection and setting of the above-mentioned preset time parameter values ​​are only for illustrating the operation process and principle of the control method. In actual applications, technical personnel in this field can flexibly adjust the specific values ​​or value ranges of the above-mentioned parameters according to the specific usage environment to meet actual needs.

[0069] Preferably, the control method of the water purification system of the present invention further comprises: opening the waste water solenoid valve 63 .

[0070] For example, after the step of opening the pressure relief valve, the pressure of the pipelines before and after the reverse osmosis filter element 2 decreases. When the user replaces the reverse osmosis filter element, the waste water solenoid valve 63 is opened to further reduce the water pressure in the reverse osmosis filter element 2 for subsequent replacement.

[0071] The control method of the water purification system of the present invention is fully described in detail below in conjunction with a specific embodiment.

[0072] like Figure 2 As shown, the water purification system of this embodiment includes a pre-filter element 1, a booster pump 4, a reverse osmosis filter element 2, a post-filter element 3, a faucet 5, a first pipeline, a second pipeline, a third pipeline 83, a first pressure relief pipeline 81, a second pressure relief pipeline 82, a controller, a filter element replacement button module, and a prompt module, which are connected in sequence. Among them, the inlet of the pre-filter element 1 is connected to the water source, the outlet of the pre-filter element 1 and the inlet of the booster pump 4 are connected to the two ends of the first pipeline respectively, the outlet of the booster pump 4 is connected to the raw water outlet of the reverse osmosis filter element 2, the pure water outlet of the reverse osmosis filter element 2 is connected to the inlet of the post-filter element 3, and the outlet of the post-filter element 3 and the faucet 5 are connected to the two ends of the second pipeline respectively. A water inlet solenoid valve 61 is provided on the pipeline where the inlet of the pre-filter element 1 is connected to the water source, a high-pressure switch 62 is provided on the second pipeline, the third pipeline 83 is connected to the waste water outlet of the reverse osmosis filter element 2, and a waste water solenoid valve 63 is provided on the third pipeline 83.

[0073] Continue reading Figure 2 The first pressure relief valve 71 is provided on the first pressure relief pipeline 81, and the second pressure relief valve 72 is provided on the second pressure relief pipeline 82. The pre-filter element 1 is provided with a first pressure relief port, which is connected to one end of the first pressure relief pipeline 81, and the other end of the first pressure relief pipeline 81 is connected to the third pipeline 83. The post-filter element 3 is provided with a second pressure relief port, which is connected to one end of the second pressure relief pipeline 82, and the other end of the second pressure relief pipeline 82 is connected to the third pipeline 83.

[0074] It should be noted that the boost pump 4, wastewater solenoid valve 63, high-pressure switch 62, water inlet solenoid valve 61, first pressure relief valve 71, second pressure relief valve 72, filter element replacement button module and prompt module are all communicatively connected to the controller so that the controller can communicate and control the above components when receiving the filter element update command signal.

[0075] In addition, it should be noted that the filter cartridge replacement button module of the water purification system of this embodiment includes a first button for replacing the pre-filter cartridge 1, a second button for replacing the post-filter cartridge 3, and a third button for replacing the reverse osmosis filter cartridge 2. The prompt module of the water purification system of this embodiment is a liquid crystal screen capable of displaying text.

[0076] The control method of the water purification system of the present invention includes the following situations:

[0077] In the first case, when the water purification system opens the water inlet solenoid valve 61 and the booster pump 4 to produce water.

[0078] When the user presses the first button for replacing the pre-filter element 1 to replace the pre-filter element 1, the controller confirms that it has received the instruction information from pressing the first button, and the controller first issues a control instruction to close the boost pump 4 and the water inlet solenoid valve 61, and then issues a control instruction to open the first pressure relief valve 71 to relieve the pressure on the pre-filter element 1. After the first pressure relief valve 71 is opened for 15 seconds, it is closed, and the controller controls the LCD screen to display the prompt message "Please replace the pre-filter element". After seeing the prompt message, the user can pull out the pre-filter element 1 for replacement.

[0079] In addition, when the user presses the third button for replacing the reverse osmosis filter element 2 to replace the reverse osmosis filter element 2, the controller confirms that it has received the instruction information from pressing the third button, and the controller first issues a control instruction to close the booster pump 4 and the water inlet solenoid valve 61, and then issues a control instruction to open the first pressure relief valve 71 to relieve pressure on the pre-filter element 1 and open the second pressure relief valve 72 to relieve pressure on the post-filter element 3. After the first pressure relief valve 71 and the second pressure relief valve 72 are both opened for 15 seconds, the first pressure relief valve 71 and the second pressure relief valve 72 are closed, and the controller finally issues a control instruction to open the wastewater solenoid valve 63 to relieve pressure on the reverse osmosis filter element 2. The controller controls the LCD screen to display the prompt message "Please replace the reverse osmosis filter element". After seeing the prompt message, the user can pull out the reverse osmosis filter element 2 for replacement.

[0080] In the second case, when the water purification system closes the water inlet solenoid valve 61 and the booster pump 4 is on standby.

[0081] When the user presses the first button for replacing the pre-filter element 1 to replace the pre-filter element 1, the controller confirms that it has received the instruction information from pressing the first button, and the controller issues a control instruction to open the first pressure relief valve 71 to relieve the pressure on the pre-filter element 1. After the first pressure relief valve 71 is opened for 15 seconds, it is closed, and the controller controls the LCD screen to display the prompt message "Please replace the pre-filter element". After seeing the prompt message, the user can pull out the pre-filter element 1 for replacement.

[0082] It should be noted that the operation of replacing the post-filter element 3 by the user is exactly the same as the operation of replacing the pre-filter element 1, so it will not be repeated here.

[0083] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A water purification system, characterized in that: It comprises a booster pump (4) and a reverse osmosis filter element (2) which are connected in sequence, a first pipeline connected to the inlet of the booster pump (4) is provided with a pre-filter element (1) and / or a second pipeline connected to the pure water outlet of the reverse osmosis filter element (2) is provided with a post-filter element (3); The water purification system further comprises a pressure relief pipeline, on which a pressure relief valve is provided, and the first pipeline and the second pipeline are respectively connected to the pressure relief pipeline or the pre-filter element (1) and the post-filter element (3) are respectively connected to the pressure relief pipeline.

2. The water purification system according to claim 1, characterized in that: The pre-filter element (1) is provided with a first pressure relief port, and the first pressure relief port is connected to the pressure relief pipeline.

3. The water purification system according to claim 1, characterized in that: The post-filter element (3) is provided with a second pressure relief port, and the second pressure relief port is communicated with the pressure relief pipeline.

4. The water purification system according to claim 1, characterized in that: The water purification system further comprises a third pipeline (83) connected to the wastewater outlet of the reverse osmosis filter element (2), a wastewater solenoid valve (63) is provided on the third pipeline (83), and the pressure relief pipeline is also connected to the third pipeline (83).

5. A control method for a water purification system according to any one of claims 1 to 4, characterized in that: The control method comprises: Determining whether the water purification system has received a filter element replacement instruction; According to the filter element replacement instruction, the pressure relief valve is selectively opened.

6. The control method of the water purification system according to claim 5, characterized in that: The step of "selectively opening the pressure relief valve according to the filter element replacement instruction" specifically includes: If the result of the filter element replacement instruction is "yes", the operating state of the booster pump (4) is obtained; The pressure relief valve is selectively opened according to the operating state of the booster pump (4).

7. The control method of the water purification system according to claim 6, characterized in that: The step of "selectively opening the pressure relief valve according to the working state of the booster pump (4)" specifically includes: If the boost pump (4) is in a stopped state, the pressure relief valve is opened.

8. The control method of the water purification system according to claim 6, characterized in that: The step of "selectively opening the pressure relief valve according to the working state of the booster pump (4)" specifically includes: If the booster pump (4) is in operation, the booster pump (4) is first turned off, and then the pressure relief valve is opened.

9. The control method of the water purification system according to claim 7 or 8, characterized in that: The control method further comprises: opening the wastewater solenoid valve (63).

10. The control method of the water purification system according to claim 5, characterized in that: The control method further comprises: after the pressure relief valve is opened for a preset time, the pressure relief valve is closed and the water purification system issues a prompt message allowing the filter element to be replaced.

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