Reverse osmosis water purifier

Abstract

The utility model provides a reverse osmosis water purifier which comprises a water inlet pump, a water inlet pipeline, a first reverse osmosis filtering unit, a second reverse osmosis filtering unit, a purified water output pipeline, a concentrated water output pipeline and a control valve group, the first reverse osmosis filter unit and the second reverse osmosis filter unit are respectively connected with a water inlet pipeline, a purified water output pipeline and a concentrated water output pipeline, the reverse osmosis water purifier further comprises a front filter element and / or a rear filter element, and the first reverse osmosis filter unit and the second reverse osmosis filter unit are connected through a switching pipeline. According to the reverse osmosis water purifier, the filtering states of the first reverse osmosis filtering unit and the second reverse osmosis filtering unit are switched through the control valve group, so that the first reverse osmosis filtering unit and the second reverse osmosis filtering unit alternately filter concentrated water, a relatively high wastewater ratio can be realized, and the problem that the reverse osmosis filtering units are frequently replaced is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of water purifiers, in particular to a reverse osmosis water purifier. Background Art

[0002] For reverse osmosis water purifiers, the wastewater ratio is an indicator that consumers and manufacturers pay more attention to. The wastewater ratio refers to the volume ratio of pure water produced by the reverse osmosis water purifier to the wastewater (also known as concentrated water) discharged per unit time.

[0003] In order to improve the wastewater ratio of reverse osmosis water purifiers, some manufacturers have designed a technical solution of double reverse osmosis filter elements, in which the concentrated water produced by one reverse osmosis filter element is transported to the water inlet of another reverse osmosis filter element, and the concentrated water produced by the other reverse osmosis filter element is discharged from the concentrated water pipeline. Since the concentrated water produced by one reverse osmosis filter element is further filtered by the other reverse osmosis filter element to obtain pure water, the concentrated water finally discharged is less and the wastewater ratio is higher.

[0004] However, since the other reverse osmosis filter element has been filtering concentrated water, it is easy to scale and reduce water output, or even become blocked. Therefore, the reverse osmosis filter element needs to be replaced frequently, which brings a lot of inconvenience to users and increases the cost of using the water purifier. Utility Model Content

[0005] In view of this, the purpose of the utility model is to provide a reverse osmosis water purifier which can improve the wastewater ratio and does not require frequent replacement of the filter element.

[0006] In order to solve the above technical problems, the technical solution used in the utility model is:

[0007] A reverse osmosis water purifier comprises an inlet pump, an inlet pipeline, a first reverse osmosis filter unit, a second reverse osmosis filter unit, a clean water output pipeline, a concentrated water output pipeline and a control valve group, wherein the inlet pump is arranged on the inlet pipeline, the first reverse osmosis filter unit and the second reverse osmosis filter unit are respectively connected to the inlet pipeline, the clean water output pipeline and the concentrated water output pipeline, the reverse osmosis water purifier also comprises a pre-filter element arranged before the inlet pump and / or a post-filter element arranged on the clean water output pipeline, the first reverse osmosis filter unit and the second reverse osmosis filter unit are connected through a switching pipeline, the control valve group is arranged on at least one of the inlet pipeline, the clean water output pipeline, the concentrated water output pipeline and the switching pipeline, and the control valve group enables the first reverse osmosis filter unit and the second reverse osmosis filter unit to alternately filter the concentrated water transported by the other reverse osmosis filter unit through the switching pipeline.

[0008] In a further preferred embodiment, the control valve group controls the reverse osmosis water purifier to switch between the first state and the second state;

[0009] When the reverse osmosis water purifier is in the first state, the raw water output by the water inlet pump enters the first reverse osmosis filtration unit, the clean water generated by filtration by the first reverse osmosis filtration unit is transported to the clean water output pipeline, the concentrated water generated by filtration by the first reverse osmosis filtration unit is transported to the second reverse osmosis filtration unit, the second reverse osmosis filtration unit filters the concentrated water of the first reverse osmosis filtration unit, the clean water generated by the second reverse osmosis filtration unit is transported to the clean water output pipeline, and the concentrated water generated by the second reverse osmosis filtration unit is transported to the concentrated water output pipeline;

[0010] When the reverse osmosis water purifier is in the second state, the raw water output by the water inlet pump enters the second reverse osmosis filtration unit, the clean water generated by filtration by the second reverse osmosis filtration unit is transported to the clean water output pipeline, the concentrated water generated by filtration by the second reverse osmosis filtration unit is transported to the first reverse osmosis filtration unit, the first reverse osmosis filtration unit filters the concentrated water of the second reverse osmosis filtration unit, the clean water generated by the first reverse osmosis filtration unit is transported to the clean water output pipeline, and the concentrated water generated by the first reverse osmosis filtration unit is transported to the concentrated water output pipeline.

[0011] In a further preferred embodiment, the first reverse osmosis filtration unit is provided with a first water inlet, a first clean water outlet, and a first concentrated water outlet, and the second reverse osmosis filtration unit is provided with a second water inlet, a second clean water outlet, and a second concentrated water outlet;

[0012] The water inlet pipeline includes a first water inlet pipeline and a second water inlet pipeline, the first water inlet pipeline is connected between the water inlet pump and the first water inlet, the second water inlet pipeline is connected between the water inlet pump and the second water inlet, and the first water inlet pipeline and the second water inlet pipeline are alternately connected;

[0013] The switching pipeline includes a first switching pipeline and a second switching pipeline, the first concentrated water outlet is connected to the second water inlet through the first switching pipeline, the second concentrated water outlet is connected to the first water inlet through the second switching pipeline, the first switching pipeline and the second switching pipeline are alternately connected, and the first concentrated water outlet and the second concentrated water outlet are also respectively connected to the concentrated water output pipeline;

[0014] The first purified water outlet and the second purified water outlet are respectively connected to the purified water output pipeline;

[0015] When the first water inlet pipeline is connected, the first switching pipeline is connected, the first concentrated water outlet is not connected to the concentrated water output pipeline, and the second concentrated water outlet is connected to the concentrated water output pipeline;

[0016] When the second water inlet pipeline is connected, the second switching pipeline is connected, the second concentrated water outlet is not connected to the concentrated water output pipeline, and the first concentrated water outlet is connected to the concentrated water output pipeline.

[0017] In a further preferred embodiment, a first water inlet valve is provided on the first water inlet pipeline, and a second water inlet valve is provided on the second water inlet pipeline, and the first water inlet valve and the second water inlet valve are opened alternately to make the first water inlet pipeline and the second water inlet pipeline alternately connected; or

[0018] The water inlet pipeline is also provided with a water inlet reversing valve, which is connected between the water inlet pump and the first water inlet pipeline and the second water inlet pipeline. The water inlet reversing valve enables the water inlet pump to be alternately connected with the first water inlet pipeline and the second water inlet pipeline.

[0019] In a further preferred embodiment, the water inlet pipeline also includes a water replenishment branch, which is connected between the water inlet pump and the first reverse osmosis filtration unit and the second reverse osmosis filtration unit. When the first water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the second water inlet through the water replenishment branch. When the second water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the first water inlet through the water replenishment branch. The flow rate of the water replenishment branch when it is in the connected state is smaller than the flow rate of the first water inlet pipeline and the second water inlet pipeline when they are in the connected state.

[0020] In a further preferred embodiment, the water replenishment branch is connected to the first switching pipeline and the second switching pipeline, a water replenishment valve is provided on the water replenishment branch, a first switching valve group is provided on the first switching pipeline, and a second switching valve group is provided on the second switching pipeline;

[0021] When the first water inlet pipeline is connected, the water supply valve is opened, the first switching valve group is opened, and the second switching valve group is closed. Part of the raw water output by the water inlet pump enters the first switching pipeline through the water supply branch, and then merges with the concentrated water produced by the first reverse osmosis filtration unit and enters the second water inlet;

[0022] When the second water inlet pipeline is connected, the water replenishment valve is opened, the second switching valve group is opened, the first switching valve group is closed, and part of the raw water output by the water inlet pump enters the second switching pipeline through the water replenishment branch, merges with the concentrated water produced by the second reverse osmosis filtration unit, and then enters the first water inlet.

[0023] In a further preferred embodiment, the first reverse osmosis filtration unit is provided with a first water inlet, a first clean water outlet, and a first concentrated water outlet, and the second reverse osmosis filtration unit is provided with a second water inlet, a second clean water outlet, and a second concentrated water outlet;

[0024] The water inlet pipeline includes a first water inlet pipeline and a second water inlet pipeline, the first water inlet pipeline is connected between the water inlet pump and the first water inlet, the second water inlet pipeline is connected between the water inlet pump and the second water inlet, and the first water inlet pipeline and the second water inlet pipeline are alternately connected;

[0025] The first concentrated water outlet is connected to the second water inlet through the switching pipeline;

[0026] The first water inlet and the second concentrated water outlet are also connected to the concentrated water output pipeline respectively, and the first clean water outlet and the second clean water outlet are connected to the clean water output pipeline respectively;

[0027] When the first water inlet pipeline is turned on, the raw water output by the water inlet pump enters the first water inlet, the concentrated water generated by the first reverse osmosis filtration unit is transported from the first concentrated water outlet to the second water inlet through the switching pipeline, and the concentrated water generated by the second reverse osmosis filtration unit is transported from the second concentrated water outlet to the concentrated water output pipeline;

[0028] When the second water inlet pipeline is connected, the raw water output by the water inlet pump enters the second concentrated water outlet, the concentrated water generated by the second reverse osmosis filtration unit is transported from the second water inlet to the first concentrated water outlet via the switching pipeline, and the concentrated water generated by the first reverse osmosis filtration unit is transported from the first water inlet to the concentrated water output pipeline.

[0029] In a further preferred embodiment, a first water inlet valve is provided on the first water inlet pipeline, a second water inlet valve is provided on the second water inlet pipeline, the reverse osmosis water purifier further comprises a first drainage pipeline and a second drainage pipeline, the first drainage pipeline is provided between the first water inlet and the concentrated water output pipeline, a first drainage valve is provided on the first drainage pipeline, the second drainage pipeline is provided between the second concentrated water outlet and the concentrated water output pipeline, and a second drainage valve is provided on the second drainage pipeline; or

[0030] A first inlet and outlet water reversing valve is arranged on the first water inlet pipeline, and a second inlet and outlet water reversing valve is arranged on the second water inlet pipeline. The reverse osmosis water purifier also includes a first drainage pipeline and a second drainage pipeline. One end of the first drainage pipeline is connected to the first inlet and outlet water reversing valve, and the other end is connected to the concentrated water output pipeline. One end of the second drainage pipeline is connected to the second inlet and outlet water reversing valve, and the other end is connected to the concentrated water output pipeline. When the first inlet and outlet water reversing valve connects the first water inlet pipeline with the first water inlet, the second inlet and outlet water reversing valve connects the second concentrated water outlet with the concentrated water output pipeline. When the first inlet and outlet water reversing valve connects the first water inlet with the first drainage pipeline, the second inlet and outlet water reversing valve connects the second water inlet pipeline with the second concentrated water outlet.

[0031] In a further preferred embodiment, the water inlet pipeline also includes a water replenishment branch, which is connected between the water inlet pump and the first reverse osmosis filtration unit and the second reverse osmosis filtration unit. When the first water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the second water inlet through the water replenishment branch. When the second water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the first concentrated water outlet through the water replenishment branch. The flow rate of the water replenishment branch when it is in the connected state is smaller than the flow rate of the first water inlet pipeline and the second water inlet pipeline when they are in the connected state.

[0032] In a further preferred embodiment, the water make-up branch is connected to the switching pipeline, and a switching valve group is provided on the switching pipeline. When the first water inlet pipeline is connected, the switching valve group connects the water make-up branch with the second water inlet, and when the second water inlet pipeline is connected, the switching valve group connects the water make-up branch with the first concentrated water outlet.

[0033] In a further preferred embodiment, the reverse osmosis water purifier also includes a concentrate return pipeline, which is connected between the concentrate output pipeline and the input end of the water inlet pump. A concentrate return valve is also provided on the concentrate return pipeline, and a concentrate valve is also provided on the concentrate output pipeline. The connection between the concentrate return pipeline and the concentrate output pipeline is located upstream of the concentrate valve.

[0034] In a further preferred embodiment, the reverse osmosis water purifier also includes a clean water return pipeline, and a clean water return valve is also provided on the clean water return pipeline. The clean water return pipeline is located between the clean water output pipeline and the input end of the water inlet pump, and is used to return the clean water in the clean water output pipeline to the input end of the water inlet pump. The tail end of the clean water return pipeline is also connected to the concentrated water return pipeline, and the clean water is returned to the input end of the water inlet pump through the concentrated water return pipeline.

[0035] In a further preferred embodiment, the reverse osmosis water purifier also includes a controller, which is electrically connected to the water inlet pump and the control valve group; the controller calculates the working life of the first reverse osmosis filter unit and the second reverse osmosis filter unit, and each time water production is started, if the time interval from the end of the last water production exceeds a first preset time, the working life of the first reverse osmosis filter unit and the second reverse osmosis filter unit are compared; if the working life of the first reverse osmosis filter unit is less than or equal to the working life of the second reverse osmosis filter unit, the controller controls the water inlet pump and the control valve group to make the reverse osmosis water purifier enter the first state; if the working life of the first reverse osmosis filter unit is greater than the working life of the second reverse osmosis filter unit, the controller controls the water inlet pump and the control valve group to make the reverse osmosis water purifier enter the second state.

[0036] The reverse osmosis water purifier of the embodiment of the utility model switches the filtering state of the first reverse osmosis filter unit and the second reverse osmosis filter unit by controlling the control valve group, so that the first reverse osmosis filter unit and the second reverse osmosis filter unit can filter concentrated water alternately. Therefore, it can achieve a higher wastewater ratio and keep the working life of the first reverse osmosis filter unit and the second reverse osmosis filter unit basically consistent, avoiding the problem of frequent replacement of reverse osmosis filter units. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other purposes, features and advantages of the present invention will become more apparent through a more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals in all the accompanying drawings indicate the same parts, and the drawings are not intentionally scaled to the actual size, but the focus is on illustrating the subject matter of the present invention.

[0038] Figure 1 and Figure 2 This is a schematic diagram of the structure of the reverse osmosis water purifier in different states according to the first embodiment of the present invention;

[0039] Figure 3 It is a structural schematic diagram of a reverse osmosis water purifier according to the second embodiment of the present invention;

[0040] Figure 4 and Figure 5 This is a schematic diagram of the structure of a reverse osmosis water purifier in different states according to Embodiment 3 of the present invention;

[0041] Figure 6 Schematic diagram of the structure of the reverse osmosis water purifier according to the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0042] The technical scheme of the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the utility model and implement it, but the examples given are not intended to limit the utility model. In the present embodiments, it should be understood that the orientations or positional relationships indicated by terms such as "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the utility model.

[0043] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element and integrated therewith, or there may be an intermediate element at the same time. The terms "installed", "one end", "the other end" and similar expressions used in this utility model are for illustrative purposes only.

[0044] Please refer to Figures 1 to 6 , the embodiment of the utility model provides a reverse osmosis water purifier, which includes a water inlet pump 10, a water inlet pipeline 20, a first reverse osmosis filter unit 30, a second reverse osmosis filter unit 40, a clean water output pipeline 60, a concentrated water output pipeline 70 and a control valve group. Of course, the reverse osmosis water purifier may also include a pre-filter element arranged before the water inlet pump 10 and a post-filter element arranged on the clean water output pipeline 60, the pre-filter element is used to filter impurities such as mud and sand, and the post-filter element is used to adjust the taste of the clean water. The pre-filter element and the post-filter element may be two independent filter elements. In an embodiment of the utility model, the pre-filter element and the post-filter element are integrated into a composite filter element. In some embodiments, only one of the pre-filter element and the post-filter element may also be provided. The first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 may be two independent reverse osmosis filter elements, or they may be integrated into a composite reverse osmosis filter element.

[0045] The water inlet pump 10 is a booster pump, which is arranged on the water inlet pipeline 20, and is used to increase the pressure of the water inlet of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40. The first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 are respectively connected to the water inlet pipeline 20, the clean water output pipeline 60, and the concentrated water output pipeline 70, and the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 are connected through the switching pipeline 50. The control valve group is arranged on at least one of the water inlet pipeline 20, the clean water output pipeline 60, the concentrated water output pipeline 70, and the switching pipeline 50, and the reverse osmosis water purifier is switched between the first state and the second state by controlling the switch of the control valve group. Specifically, in the embodiment of the utility model, the water inlet valve on the water inlet pipeline 20, the concentrated water valve 71 on the concentrated water output pipeline 70, the switching valve on the switching pipeline 50, and the one-way valve on the clean water output pipeline 60 are all part of the control valve group, while in other embodiments, the control valve group may not be provided on some pipelines (such as the switching pipeline 50). The valves in the control valve group can all be solenoid valves.

[0046] Please refer to Figure 1 , Figure 3 and Figure 4, the dotted arrow in the figure indicates the direction of concentrated water. When the reverse osmosis water purifier is in the first state, raw water (such as tap water) enters the water inlet pump 10, and the water inlet pump 10 pressurizes the raw water and then outputs it, and the output raw water enters the first reverse osmosis filter unit 30, and the clean water filtered by the first reverse osmosis filter unit 30 is transported to the clean water output pipeline 60, and the concentrated water filtered by the first reverse osmosis filter unit 30 is transported to the second reverse osmosis filter unit 40, and the second reverse osmosis filter unit 40 filters the concentrated water of the first reverse osmosis filter unit 30, and the clean water produced by the second reverse osmosis filter unit 40 is also transported to the clean water output pipeline 60, and the concentrated water produced by the second reverse osmosis filter unit 40 is transported to the concentrated water output pipeline 70.

[0047] Please refer to Figure 2 and Figure 5 When the reverse osmosis water purifier is in the second state, the raw water output by the water inlet pump 10 enters the second reverse osmosis filter unit 40, the clean water generated by the filtration of the second reverse osmosis filter unit 40 is transported to the clean water output pipeline 60, the concentrated water generated by the filtration of the second reverse osmosis filter unit 40 is transported to the first reverse osmosis filter unit 30, the first reverse osmosis filter unit 30 filters the concentrated water of the second reverse osmosis filter unit 40, the clean water generated by the first reverse osmosis filter unit 30 is transported to the clean water output pipeline, and the concentrated water generated by the first reverse osmosis filter unit 30 is transported to the concentrated water output pipeline.

[0048] The reverse osmosis water purifier of the embodiment of the utility model can switch the filtering states of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 by controlling the control valve group, so that the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 can alternately filter concentrated water. Therefore, a higher wastewater ratio can be achieved, and the working life of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 can be basically consistent, avoiding the problem of frequently replacing one of the reverse osmosis filter elements in the related art.

[0049] Please refer to Figures 1 to 3 In a preferred embodiment, the first reverse osmosis filtration unit 30 is provided with a first water inlet 31, a first clean water outlet 32, and a first concentrated water outlet 33, and the second reverse osmosis filtration unit 40 is provided with a second water inlet 41, a second clean water outlet 42, and a second concentrated water outlet 43.

[0050] The water inlet pipeline 20 includes a first water inlet pipeline 21 and a second water inlet pipeline 22 connected in parallel. The first water inlet pipeline 21 is connected between the water inlet pump 10 and the first water inlet 31, and the second water inlet pipeline 22 is connected between the water inlet pump 10 and the second water inlet 41. The first water inlet pipeline 21 and the second water inlet pipeline 22 are alternately connected through the switch of the control valve group.

[0051] The switching pipeline 50 includes a first switching pipeline 51 and a second switching pipeline 52. The first concentrated water outlet 33 is connected to the second water inlet 41 through the first switching pipeline 51, and the second concentrated water outlet 43 is connected to the first water inlet 31 through the second switching pipeline 52. The first switching pipeline 51 and the second switching pipeline 52 are alternately connected. The first concentrated water outlet 33 and the second concentrated water outlet 43 are also respectively connected to the concentrated water output pipeline 70. In the first embodiment and the second embodiment, the first switching pipeline 51 and the second switching pipeline 52 are both composed of multiple sections of pipelines, and the first switching pipeline 51 and the second switching pipeline 52 are both provided with multiple one-way valves 53 (a part of the control valve group). By controlling the multiple one-way valves, the first switching pipeline 51 and the second switching pipeline 52 are alternately connected. In these two embodiments, the first switching pipeline 51 and the second switching pipeline 52 can also share a part of the pipeline. In other embodiments, the first switching pipeline 51 and the second switching pipeline 52 can also be independent of each other.

[0052] The first purified water outlet 32 ​​and the second purified water outlet 42 are respectively connected to the purified water output pipeline 60, so that the purified water (also called pure water) produced by the first reverse osmosis filtration unit 30 and the second reverse osmosis filtration unit 40 can be output through the purified water output pipeline 60 for user use.

[0053] When the reverse osmosis water purifier is in the first state, the first water inlet pipeline 21 is connected, the second water inlet pipeline 22 is not connected, the first switching pipeline 51 is connected, the second switching pipeline 52 is not connected, the first concentrated water outlet 33 is not connected to the concentrated water output pipeline 70, and the second concentrated water outlet 43 is connected to the concentrated water output pipeline 70. The first water inlet pipeline 21 is connected here, which means that the raw water output by the water inlet pump 10 can be transported to the first water inlet 31 through the first water inlet pipeline 21. In this state, the first reverse osmosis filtration unit 30 filters the raw water to obtain clean water and concentrated water. The clean water is transported from the first clean water outlet 32 ​​to the clean water output pipeline 60, and the concentrated water is transported to the second water inlet 41 through the first concentrated water outlet 33 and the first switching pipeline 51. The second reverse osmosis filtration unit 40 further filters the concentrated water of the first reverse osmosis filtration unit 30 to obtain clean water and concentrated water. The clean water is transported to the clean water output pipeline 60 through the second clean water outlet 42, and the concentrated water is transported to the concentrated water output pipeline 70 through the second concentrated water outlet 43 and the second drainage pipeline 74. The concentrated water discharge pipeline 74 can be provided with a second drainage valve 75, which can be a normally closed valve. The first concentrated water outlet 33 can be connected to the concentrated water output pipeline 70 through the first drainage pipeline 72, and the first drainage pipeline 72 can be provided with a first drainage valve 73, which can be a normally closed valve. In this state, the second drainage valve 75 is opened and the first drainage valve 73 is closed.

[0054] When the reverse osmosis water purifier is in the second state, the second water inlet pipeline 22 is connected, the first water inlet pipeline 21 is not connected, the second switching pipeline 52 is connected, the first switching pipeline 51 is not connected, the second concentrated water outlet 43 is not connected to the concentrated water output pipeline 70, and the first concentrated water outlet 33 is connected to the concentrated water output pipeline 70. In this state, the raw water output by the water inlet pump 10 can be transported to the second water inlet 41 through the second water inlet pipeline 22. The second reverse osmosis filtration unit 40 filters the raw water to obtain clean water and concentrated water. The clean water is transported from the second clean water outlet 42 to the clean water output pipeline 60, and the concentrated water is transported to the first water inlet 41 through the second switching pipeline 52. The first reverse osmosis filtration unit 30 further filters the concentrated water of the second reverse osmosis filtration unit 40 to obtain clean water and concentrated water. The clean water is transported to the clean water output pipeline 60 through the first clean water outlet 32, and the concentrated water is transported to the concentrated water output pipeline 70 through the first concentrated water outlet 33 and the first drainage pipeline 72. In this state, the second drainage valve 75 is closed and the first drainage valve 73 is opened.

[0055] Please refer to Figure 1 and Figure 2 In the first embodiment, a first water inlet valve 24 is provided on the first water inlet pipeline 21, and a second water inlet valve 25 is provided on the second water inlet pipeline 22. The first water inlet valve 24 and the second water inlet valve 25 are opened alternately, so that the first water inlet pipeline 21 and the second water inlet pipeline 22 are alternately conducted.

[0056] Please refer to Figure 3 In the second embodiment, a water inlet reversing valve 28 is provided on the water inlet pipeline 20, and the water inlet reversing valve 28 is connected between the water inlet pump 10 and the first water inlet pipeline 21 and the second water inlet pipeline 22. The water inlet reversing valve 28 enables the water inlet pump 10 to be alternately connected to the first water inlet pipeline 21 and the second water inlet pipeline 22. The water inlet reversing valve 28 can be a two-position three-way reversing solenoid valve. In the first state, the first water inlet pipeline 21 is connected to the water inlet pump 10, and the second water inlet pipeline 22 is not connected to the water inlet pump 10; in the second state, the second water inlet pipeline 22 is connected to the water inlet pump 10, and the first water inlet pipeline 21 is not connected to the water inlet pump 10. Similarly, in this embodiment, the first drain valve 73 and the second drain valve 75 are also replaced by the concentrate discharge reversing valve 76 , and the concentrate discharge reversing valve 76 enables the first drain pipeline 72 , the second drain pipeline 74 and the concentrate output pipeline 70 to be alternately connected.

[0057] Please refer to Figures 1 to 3In a further preferred embodiment, the water inlet pipeline 20 also includes a water replenishment branch 23, which is connected between the water inlet pump 10 and the first reverse osmosis filtration unit 30 and the second reverse osmosis filtration unit 40. When the first water inlet pipeline 21 is turned on, the water replenishment branch 23 is turned on, and the water inlet pump 10 replenishes raw water to the second water inlet 41 through the water replenishment branch 23. When the second water inlet pipeline 22 is turned on, the water replenishment branch 23 is turned on, and the water inlet pump 10 replenishes raw water to the first water inlet 31 through the water replenishment branch 23. The flow rate of the water replenishment branch 23 when it is in the turned-on state is less than the flow rate of the first water inlet pipeline 21 and the second water inlet pipeline 22 when they are in the turned-on state. Since the water production capacity of the reverse osmosis membrane is related to its working pressure, when the water inlet pressure is low, the water production capacity is also poor. For the secondary filter element of the reverse osmosis water purifier, if only the concentrated water of the primary filter element is filtered, the concentrated water inlet pressure is low. Therefore, by replenishing raw water through the water replenishment branch 23, the water inlet pressure of the secondary filter element can be increased, and its water production capacity can be improved. The primary filter element and the secondary filter element referred to here are defined according to the filtration level of water. In the first state, the first reverse osmosis filter unit 30 is a primary filter element, and the second reverse osmosis filter unit 40 is a secondary filter element. In the second state, the second reverse osmosis filter unit 40 is a primary filter element, and the first reverse osmosis filter unit 30 is a secondary filter element. The ratio of the flow rate of the first water inlet pipeline 21 and the second water inlet pipeline 22 in the conductive state to the flow rate of the water replenishment branch 23 in the conductive state can be 2-10. If the ratio is too small, the water production capacity of the primary filter element will be reduced. If the ratio is too large, the water production capacity of the secondary filter element will be reduced.

[0058] In a further preferred embodiment, the water replenishment branch 23 is connected to the first switching pipeline 51 and the second switching pipeline 52, a water replenishment valve 26 is provided on the water replenishment branch 51, a first switching valve group (that is, two one-way valves 53 on the first switching pipeline 51) is provided on the first switching pipeline 51, and a second switching valve group (that is, two one-way valves 53 on the second switching pipeline 52) is provided on the second switching pipeline 52.

[0059] When the first water inlet pipeline 21 is connected, the water replenishment valve 26 is opened, the first switching valve group is opened, and the second switching valve group is closed. Part of the raw water output by the water inlet pump 10 enters the first switching pipeline 51 through the water replenishment branch 23, and then merges with the concentrated water produced by the first reverse osmosis filtration unit 30 and enters the second water inlet 41.

[0060] When the second water inlet pipeline 22 is connected, the water replenishment valve 26 is opened, the second switching valve group is opened, and the first switching valve group is closed. Part of the raw water output by the water inlet pump 10 enters the second switching pipeline 52 through the water replenishment branch 23, and then merges with the concentrated water produced by the second reverse osmosis filtration unit 40 and enters the first water inlet 31.

[0061] In other embodiments, the water replenishment branch 23 may not be connected to the first switching pipeline 51 and the second switching pipeline 52, but may be directly connected to the first water inlet 31 and the second water inlet 41, which will not be described in detail here.

[0062] Please refer to Figures 4 to 6 In the third and fourth embodiments, the first reverse osmosis filtration unit 30 is provided with a first water inlet 31, a first clean water outlet 32, and a first concentrated water outlet 33, and the second reverse osmosis filtration unit 40 is provided with a second water inlet 41, a second clean water outlet 42, and a second concentrated water outlet 43.

[0063] The water inlet pipeline 20 includes a first water inlet pipeline 21 and a second water inlet pipeline 22. The first water inlet pipeline 21 is connected between the water inlet pump 10 and the first water inlet 31, and the second water inlet pipeline 22 is connected between the water inlet pump 10 and the second water inlet 41. The first water inlet pipeline 21 and the second water inlet pipeline 22 are alternately connected.

[0064] The first concentrated water outlet 33 is connected to the second water inlet 41 via a switching pipeline 50. The first water inlet 31 and the second concentrated water outlet 43 are also connected to concentrated water output pipelines 70, respectively. The first purified water outlet 32 ​​and the second purified water outlet 42 are connected to purified water output pipelines 60, respectively.

[0065] When the reverse osmosis water purifier is in the first state, the raw water output by the water inlet pump 10 enters the first water inlet 31, the concentrated water generated by filtration by the first reverse osmosis filtration unit 30 is transported from the first concentrated water outlet 33 to the second water inlet 41 via the switching pipeline 50, and the concentrated water generated by filtration by the second reverse osmosis filtration unit 40 is transported from the second concentrated water outlet 43 to the concentrated water output pipeline 70.

[0066] When the reverse osmosis water purifier is in the second state, the raw water output by the water inlet pump 10 enters the second concentrated water outlet 43, the concentrated water generated by the filtration of the second reverse osmosis filtration unit 40 is transported from the second water inlet 41 to the first concentrated water outlet 33 via the switching pipeline 50, and the concentrated water generated by the filtration of the first reverse osmosis filtration unit 30 is transported from the first water inlet 31 to the concentrated water output pipeline 70.

[0067] The difference between the third and fourth embodiments and the first and second embodiments is that, in the second state, the water inlet direction of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 is opposite to that in the first state, that is, water is inletted from the concentrated water outlet and water is outlet from the water inlet. For the reverse osmosis filter element, if water is continuously inletted from the water inlet, although the reverse osmosis membrane near the water inlet still has a good filtering state, the reverse osmosis membrane near the concentrated water outlet is immersed in high-concentration concentrated water for a long time, which is easy to scale and reduce water outlet, or even blocked, so the filter element has to be replaced, and the reverse osmosis membrane is not fully utilized. Through the technical solutions of the third and fourth embodiments, since the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 are forwardly inletted (water is inletted from the water inlet) in the first state and reversely inletted (water is inletted from the concentrated water outlet) in the second state, the reverse osmosis membrane can be fully utilized and the service life of the filter element is improved.

[0068] It should be noted that in the above embodiment, since the functions of the water inlet and the concentrate outlet are interchangeable, the water inlet and concentrate outlet are merely names set to distinguish different water outlets, and it is not limited to the water inlet that can only take in water and the concentrate outlet that can only discharge concentrate.

[0069] Please refer to Figure 4 and Figure 5 In the third embodiment, a first water inlet valve 24 is provided on the first water inlet pipeline 21, a second water inlet valve 25 is provided on the second water inlet pipeline 22, and the reverse osmosis water purifier further includes a first drainage pipeline 72 and a second drainage pipeline 74. The first drainage pipeline 72 is provided between the first water inlet 31 and the concentrated water output pipeline 70, a first drainage valve 73 is provided on the first drainage pipeline 72, the second drainage pipeline 74 is provided between the second concentrated water outlet 43 and the concentrated water output pipeline 70, and a second drainage valve 75 is provided on the second drainage pipeline 74. In the first state, the first water inlet valve 24 is opened, the second water inlet valve 25 is closed, the second drainage valve 75 is opened, and the first drainage valve 73 is closed. In the second state, the second water inlet valve 25 is opened, the first water inlet valve 24 is closed, the second drainage valve 75 is closed, and the first drainage valve 73 is opened.

[0070] Please refer to Figure 6In the fourth embodiment, a first water inlet and outlet reversing valve 27 is provided on the first water inlet pipeline 21, and a second water inlet and outlet reversing valve 29 is provided on the second water inlet pipeline 22. Both the first water inlet and outlet reversing valve 27 and the second water inlet and outlet reversing valve 29 can be two-position three-way reversing solenoid valves. The reverse osmosis water purifier also includes a first drainage pipeline 73 and a second drainage pipeline 74, one end of the first drainage pipeline 73 is connected to the first water inlet and outlet reversing valve 27, and the other end is connected to the concentrated water output pipeline 70, one end of the second drainage pipeline 74 is connected to the second water inlet and outlet reversing valve 29, and the other end is connected to the concentrated water output pipeline 70. When the reverse osmosis water purifier is in the first state, the first water inlet and outlet reversing valve 27 conducts the first water inlet pipeline 21 and the first water inlet 31, and the second water inlet and outlet reversing valve 29 conducts the second concentrated water outlet 43 and the concentrated water output pipeline 70. When the reverse osmosis water purifier is in the second state, the first water inlet and outlet reversing valve 27 connects the first water inlet 31 with the first drainage pipe 73, and the second water inlet and outlet reversing valve 29 connects the second water inlet pipe 2 with the second concentrated water outlet 43. The water flow direction of the fourth embodiment is basically the same as that of the third embodiment, which will not be repeated here.

[0071] Please refer to Figure 6 In a further preferred embodiment, the water inlet pipeline 20 further includes a water replenishment branch 23, which is connected between the water inlet pump 10 and the first reverse osmosis filtration unit 30 and the second reverse osmosis filtration unit 40. When the first water inlet pipeline 21 is turned on, the water replenishment branch 23 is turned on, and the water inlet pump 10 replenishes raw water to the second water inlet 41 through the water replenishment branch 23. When the second water inlet pipeline 22 is turned on, the water replenishment branch 23 is turned on, and the water inlet pump 10 replenishes raw water to the first concentrated water outlet 33 through the water replenishment branch 23. The flow rate of the water replenishment branch 23 when it is turned on is less than the flow rate of the first water inlet pipeline 21 and the second water inlet pipeline 22 when they are turned on. In this embodiment, the function of the water replenishment branch 23 is similar to that of the above-mentioned embodiments one and two, and will not be repeated here.

[0072] Please refer to Figure 6 In the fourth embodiment, the water replenishment branch 23 is connected to the switching pipeline 50, and the switching pipeline 50 is provided with a switching valve group 58. When the first water inlet pipeline 21 is connected, the switching valve group 58 connects the water replenishment branch 23 with the second water inlet 41. When the second water inlet pipeline 22 is connected, the switching valve group 58 connects the water replenishment branch 23 with the first concentrated water outlet 33. It should be noted that although Figure 4 and Figure 5The water replenishment branch 23 and the switching valve group 58 are not shown in the figure, but the water replenishment branch 23 can also be set in the same way as in the fourth embodiment in the third embodiment. The switching valve group 58 can be composed of a plurality of solenoid valves. On the one hand, it is necessary to ensure the conduction of the switching pipeline 50, and on the other hand, it is necessary to ensure that the raw water flow direction from the water replenishment branch 23 to the switching pipeline 50 is consistent with the concentrated water flow direction of the switching pipeline 50 itself. For example, the switching valve group 58 can be composed of a two-position three-way reversing solenoid valve and a normally open two-way valve, or it can be composed of two two-way valves and a normally open two-way valve. Of course, the water replenishment branch 23 can also be not connected to the switching pipeline 50, but directly connected to the first concentrated water outlet 33 and the second water inlet 41, which will not be repeated here.

[0073] Please refer to Figures 1 to 6 The reverse osmosis water purifier also includes a brine return line 80, which is connected between the brine output line 70 and the input end of the water inlet pump 10. A brine return valve 81 is also provided on the brine return line 80, and a brine valve 71 is also provided on the brine output line 70. The connection between the brine return line 80 and the brine output line 70 is located upstream of the brine valve 71. By returning the brine to the input end of the water inlet pump 10, the brine flow rate can be increased, thereby increasing the surface flow rate of the reverse osmosis membrane in the first reverse osmosis filtration unit 30 and the second reverse osmosis filtration unit 40, preventing flow attenuation, and also improving the wastewater ratio of the reverse osmosis water purifier. When the brine is refluxed, the brine valve 71 can be closed, the brine return valve 81 can be opened, or both can be opened.

[0074] In a further preferred embodiment, the reverse osmosis water purifier further comprises a clean water return pipeline 90, on which a clean water return valve 91 and a return check valve 92 are further arranged. The clean water return pipeline 90 is located between the clean water output pipeline 60 and the input end of the water inlet pump 10, and is used to return the clean water of the clean water output pipeline 60 to the input end of the water inlet pump 10. The tail end of the clean water return pipeline 60 is also connected to the concentrated water return pipeline 80, and the clean water is returned to the input end of the water inlet pump 10 through the concentrated water return pipeline 80. When the reverse osmosis water purifier starts to make water, if the interval time from the last water making is long, the clean water return can be started at the beginning of water making, so that the clean water return valve 91 is opened for about 10 seconds to reduce the TDS value of the first cup of water. The return check valve 92 can prevent the concentrated water of the concentrated water return pipeline 80 from entering the clean water return pipeline 90. A high pressure switch may also be provided on the purified water output pipeline 60. When the high pressure switch detects that the pressure on the purified water outlet side is high, the purified water reflux may also be started. A flow meter 61, a TDS sensor and a high pressure switch may also be provided on the purified water output pipeline 60.

[0075] In a preferred embodiment, the reverse osmosis water purifier further includes a controller (not shown), which is electrically connected to the water inlet pump 10 and the control valve group. The controller calculates the working life of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40. Each time water production is started, if the time interval between the last water production and the end exceeds the first preset time (e.g., 5 minutes), the working life of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 is compared. If the working life of the first reverse osmosis filter unit 30 is less than or equal to the working life of the second reverse osmosis filter unit 40, the controller controls the water inlet pump 10 and the control valve group to make the reverse osmosis water purifier enter the first state. If the working life of the first reverse osmosis filter unit 30 is greater than the working life of the second reverse osmosis filter unit 40, the controller controls the water inlet pump 10 and the control valve group to make the reverse osmosis water purifier enter the second state. By setting in this way, the working life of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 is kept in a substantially consistent state. Each time water production is started, if the time interval from the end of the last water production does not exceed the first preset time, the last water production state is maintained.

[0076] In a further preferred embodiment, when the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40 are initially installed (including replacement of the filter element), the controller assigns an initial value (e.g., 100) to the working life of the first reverse osmosis filter unit 30 and the second reverse osmosis filter unit 40. When the reverse osmosis water purifier works in the first state for a second preset time (e.g., 1 minute), the working life of the first reverse osmosis filter unit 30 is +1, and the working life of the second reverse osmosis filter unit 40 is -1. When the reverse osmosis water purifier works in the second state for a second preset time, the working life of the second reverse osmosis filter unit 40 is +1, and the working life of the first reverse osmosis filter unit 30 is -1. Of course, in some cases (e.g., the reverse osmosis water purifier enters a hot water mode with a small purified water outlet flow), the reverse osmosis water purifier may also use only the first reverse osmosis filter unit 30 or the second reverse osmosis filter unit 40 for filtration, and at this time, the switching pipeline 50 may be made non-conductive. In this case, when the reverse osmosis water purifier works for the second preset time, only the working life of the first reverse osmosis filtration unit 30 or the second reverse osmosis filtration unit 40 in the filtering state is increased by 1, and the working life of the unit not filtering remains unchanged. In other embodiments, the working life of the first reverse osmosis filtration unit 30 and the second reverse osmosis filtration unit 40 can also be calculated by counting the purified water output or by other methods.

[0077] In this specification, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0078] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "other embodiments" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0079] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A reverse osmosis water purifier, comprising a water inlet pump, a water inlet pipeline, a first reverse osmosis filter unit, a second reverse osmosis filter unit, a clean water output pipeline, a concentrated water output pipeline and a control valve group, wherein the water inlet pump is arranged on the water inlet pipeline, the first reverse osmosis filter unit and the second reverse osmosis filter unit are respectively connected to the water inlet pipeline, the clean water output pipeline and the concentrated water output pipeline, the reverse osmosis water purifier further comprises a pre-filter element arranged before the water inlet pump and / or a post-filter element arranged on the clean water output pipeline, characterized in that: The first reverse osmosis filtration unit and the second reverse osmosis filtration unit are connected via a switching pipeline. The control valve group is arranged on at least one of the water inlet pipeline, the clean water output pipeline, the concentrated water output pipeline, and the switching pipeline. The control valve group enables the first reverse osmosis filtration unit and the second reverse osmosis filtration unit to alternately filter the concentrated water transported by the other reverse osmosis filtration unit through the switching pipeline.

2. The reverse osmosis water purifier according to claim 1, characterized in that: The control valve group controls the reverse osmosis water purifier to switch between a first state and a second state; When the reverse osmosis water purifier is in the first state, the raw water output by the water inlet pump enters the first reverse osmosis filtration unit, the clean water generated by filtration by the first reverse osmosis filtration unit is transported to the clean water output pipeline, the concentrated water generated by filtration by the first reverse osmosis filtration unit is transported to the second reverse osmosis filtration unit, the second reverse osmosis filtration unit filters the concentrated water of the first reverse osmosis filtration unit, the clean water generated by the second reverse osmosis filtration unit is transported to the clean water output pipeline, and the concentrated water generated by the second reverse osmosis filtration unit is transported to the concentrated water output pipeline; When the reverse osmosis water purifier is in the second state, the raw water output by the water inlet pump enters the second reverse osmosis filtration unit, the clean water generated by filtration by the second reverse osmosis filtration unit is transported to the clean water output pipeline, the concentrated water generated by filtration by the second reverse osmosis filtration unit is transported to the first reverse osmosis filtration unit, the first reverse osmosis filtration unit filters the concentrated water of the second reverse osmosis filtration unit, the clean water generated by the first reverse osmosis filtration unit is transported to the clean water output pipeline, and the concentrated water generated by the first reverse osmosis filtration unit is transported to the concentrated water output pipeline.

3. The reverse osmosis water purifier according to claim 1, characterized in that: The first reverse osmosis filtration unit is provided with a first water inlet, a first clean water outlet, and a first concentrated water outlet, and the second reverse osmosis filtration unit is provided with a second water inlet, a second clean water outlet, and a second concentrated water outlet; The water inlet pipeline includes a first water inlet pipeline and a second water inlet pipeline, the first water inlet pipeline is connected between the water inlet pump and the first water inlet, the second water inlet pipeline is connected between the water inlet pump and the second water inlet, and the first water inlet pipeline and the second water inlet pipeline are alternately connected; The switching pipeline includes a first switching pipeline and a second switching pipeline, the first concentrated water outlet is connected to the second water inlet through the first switching pipeline, the second concentrated water outlet is connected to the first water inlet through the second switching pipeline, the first switching pipeline and the second switching pipeline are alternately connected, and the first concentrated water outlet and the second concentrated water outlet are also respectively connected to the concentrated water output pipeline; The first purified water outlet and the second purified water outlet are respectively connected to the purified water output pipeline; When the first water inlet pipeline is connected, the first switching pipeline is connected, the first concentrated water outlet is not connected to the concentrated water output pipeline, and the second concentrated water outlet is connected to the concentrated water output pipeline; When the second water inlet pipeline is connected, the second switching pipeline is connected, the second concentrated water outlet is not connected to the concentrated water output pipeline, and the first concentrated water outlet is connected to the concentrated water output pipeline.

4. The reverse osmosis water purifier according to claim 3, characterized in that: The first water inlet pipeline is provided with a first water inlet valve, the second water inlet pipeline is provided with a second water inlet valve, the first water inlet valve and the second water inlet valve are opened alternately, so that the first water inlet pipeline and the second water inlet pipeline are alternately connected; or The water inlet pipeline is also provided with a water inlet reversing valve, which is connected between the water inlet pump and the first water inlet pipeline and the second water inlet pipeline. The water inlet reversing valve enables the water inlet pump to be alternately connected with the first water inlet pipeline and the second water inlet pipeline.

5. The reverse osmosis water purifier according to claim 3, characterized in that: The water inlet pipeline also includes a water replenishment branch, which is connected between the water inlet pump and the first reverse osmosis filtration unit and the second reverse osmosis filtration unit. When the first water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the second water inlet through the water replenishment branch. When the second water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the first water inlet through the water replenishment branch. The flow rate of the water replenishment branch in the connected state is smaller than the flow rates of the first water inlet pipeline and the second water inlet pipeline when they are in the connected state.

6. The reverse osmosis water purifier according to claim 5, characterized in that: The water replenishment branch is connected to the first switching pipeline and the second switching pipeline, a water replenishment valve is provided on the water replenishment branch, a first switching valve group is provided on the first switching pipeline, and a second switching valve group is provided on the second switching pipeline; When the first water inlet pipeline is connected, the water supply valve is opened, the first switching valve group is opened, and the second switching valve group is closed. Part of the raw water output by the water inlet pump enters the first switching pipeline through the water supply branch, and then merges with the concentrated water produced by the first reverse osmosis filtration unit and enters the second water inlet; When the second water inlet pipeline is connected, the water replenishment valve is opened, the second switching valve group is opened, the first switching valve group is closed, and part of the raw water output by the water inlet pump enters the second switching pipeline through the water replenishment branch, merges with the concentrated water produced by the second reverse osmosis filtration unit, and then enters the first water inlet.

7. The reverse osmosis water purifier according to claim 1, characterized in that: The first reverse osmosis filtration unit is provided with a first water inlet, a first clean water outlet, and a first concentrated water outlet, and the second reverse osmosis filtration unit is provided with a second water inlet, a second clean water outlet, and a second concentrated water outlet; The water inlet pipeline includes a first water inlet pipeline and a second water inlet pipeline, the first water inlet pipeline is connected between the water inlet pump and the first water inlet, the second water inlet pipeline is connected between the water inlet pump and the second water inlet, and the first water inlet pipeline and the second water inlet pipeline are alternately connected; The first concentrated water outlet is connected to the second water inlet through the switching pipeline; The first water inlet and the second concentrated water outlet are also connected to the concentrated water output pipeline respectively, and the first clean water outlet and the second clean water outlet are connected to the clean water output pipeline respectively; When the first water inlet pipeline is turned on, the raw water output by the water inlet pump enters the first water inlet, the concentrated water generated by the first reverse osmosis filtration unit is transported from the first concentrated water outlet to the second water inlet through the switching pipeline, and the concentrated water generated by the second reverse osmosis filtration unit is transported from the second concentrated water outlet to the concentrated water output pipeline; When the second water inlet pipeline is connected, the raw water output by the water inlet pump enters the second concentrated water outlet, the concentrated water generated by the second reverse osmosis filtration unit is transported from the second water inlet to the first concentrated water outlet via the switching pipeline, and the concentrated water generated by the first reverse osmosis filtration unit is transported from the first water inlet to the concentrated water output pipeline.

8. The reverse osmosis water purifier according to claim 7, characterized in that: A first water inlet valve is provided on the first water inlet pipeline, a second water inlet valve is provided on the second water inlet pipeline, the reverse osmosis water purifier further comprises a first drainage pipeline and a second drainage pipeline, the first drainage pipeline is provided between the first water inlet and the concentrated water output pipeline, a first drainage valve is provided on the first drainage pipeline, the second drainage pipeline is provided between the second concentrated water outlet and the concentrated water output pipeline, and a second drainage valve is provided on the second drainage pipeline; or A first inlet and outlet water reversing valve is arranged on the first water inlet pipeline, and a second inlet and outlet water reversing valve is arranged on the second water inlet pipeline. The reverse osmosis water purifier also includes a first drainage pipeline and a second drainage pipeline. One end of the first drainage pipeline is connected to the first inlet and outlet water reversing valve, and the other end is connected to the concentrated water output pipeline. One end of the second drainage pipeline is connected to the second inlet and outlet water reversing valve, and the other end is connected to the concentrated water output pipeline. When the first inlet and outlet water reversing valve connects the first water inlet pipeline with the first water inlet, the second inlet and outlet water reversing valve connects the second concentrated water outlet with the concentrated water output pipeline. When the first inlet and outlet water reversing valve connects the first water inlet with the first drainage pipeline, the second inlet and outlet water reversing valve connects the second water inlet pipeline with the second concentrated water outlet.

9. The reverse osmosis water purifier according to claim 7, characterized in that: The water inlet pipeline also includes a water replenishment branch, which is connected between the water inlet pump and the first reverse osmosis filtration unit and the second reverse osmosis filtration unit. When the first water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the second water inlet through the water replenishment branch. When the second water inlet pipeline is connected, the water replenishment branch is connected, and the water inlet pump replenishes raw water to the first concentrated water outlet through the water replenishment branch. The flow rate of the water replenishment branch in the connected state is smaller than the flow rates of the first water inlet pipeline and the second water inlet pipeline when they are in the connected state.

10. The reverse osmosis water purifier according to claim 9, characterized in that: The water replenishment branch is connected to the switching pipeline, and a switching valve group is arranged on the switching pipeline. When the first water inlet pipeline is connected, the switching valve group connects the water replenishment branch with the second water inlet, and when the second water inlet pipeline is connected, the switching valve group connects the water replenishment branch with the first concentrated water outlet.

11. The reverse osmosis water purifier according to any one of claims 1 to 10, characterized in that: The reverse osmosis water purifier also includes a concentrate return pipeline, which is connected between the concentrate output pipeline and the input end of the water inlet pump. A concentrate return valve is also provided on the concentrate return pipeline. A concentrate valve is also provided on the concentrate output pipeline. The connection between the concentrate return pipeline and the concentrate output pipeline is located upstream of the concentrate valve.

12. The reverse osmosis water purifier according to claim 11, characterized in that: The reverse osmosis water purifier also includes a clean water return pipeline, on which a clean water return valve is also arranged. The clean water return pipeline is located between the clean water output pipeline and the input end of the water inlet pump, and is used to return the clean water in the clean water output pipeline to the input end of the water inlet pump. The tail end of the clean water return pipeline is also connected to the concentrated water return pipeline, and the clean water is returned to the input end of the water inlet pump through the concentrated water return pipeline.

13. The reverse osmosis water purifier according to claim 2, characterized in that: The reverse osmosis water purifier also includes a controller, which is electrically connected to the water inlet pump and the control valve group; the controller calculates the working life of the first reverse osmosis filter unit and the second reverse osmosis filter unit, and each time water production is started, if the time interval from the last water production end exceeds the first preset time, the working life of the first reverse osmosis filter unit and the second reverse osmosis filter unit are compared; if the working life of the first reverse osmosis filter unit is less than or equal to the working life of the second reverse osmosis filter unit, the controller controls the water inlet pump and the control valve group to make the reverse osmosis water purifier enter the first state; if the working life of the first reverse osmosis filter unit is greater than the working life of the second reverse osmosis filter unit, the controller controls the water inlet pump and the control valve group to make the reverse osmosis water purifier enter the second state.

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