CN114135695A

CN114135695A - Water return valve and water supply system

Info

Publication number: CN114135695A
Application number: CN202111460951.3A
Authority: CN
Inventors: 巴喜亮; 梁国荣
Original assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Priority date: 2021-04-30
Filing date: 2021-11-30
Publication date: 2022-03-04
Also published as: CN114135694A; CN216715309U; CN216715308U

Abstract

The invention discloses a water return valve and a water supply system. The water return valve comprises a valve body and a circulating valve; the valve body is provided with a hot runner, a cold runner and a circulating runner; a circulating inlet is arranged between the water inlet end and the water outlet end of the hot runner; a circulating outlet is arranged between the water inlet end and the water outlet end of the cold runner; the circulation flow channel is used for communicating the circulation inlet with the circulation outlet; the circulation valve is disposed in the circulation flow passage, and has an initial position closing the circulation inlet, and a circulation position opening the circulation inlet by a fluid pressure in the hot runner. The water return valve disclosed by the invention has a water return function, so that cold water remained in a tail end pipeline of a water supply system flows back to the water heater through the water return valve to be preheated and then supplied to a user, and the output of cold water at the initial stage of starting the water supply system is reduced.

Description

Water return valve and water supply system

PRIORITY INFORMATION

The present application claims priority to "application No. 202120956351.5 entitled communication valve, return valve, pressure valve assembly and water supply system, applied on 30/4/2021" and "application No. 202120955921.9 entitled communication valve, return valve, pressure valve assembly and water supply system, applied on 30/4/2021".

Technical Field

The invention relates to the technical field of water supply systems, in particular to a water return valve and a water supply system.

Background

In the related art, a water supply system is generally applied to supply hot and cold water to a user. The traditional water supply system generally comprises a water heater, a cold water pipe, a hot water pipe, a pressure valve, a water mixing device and other structures; the water outlet pipe of the water heater is connected with the hot water inlet end of the water mixing device through a hot water pipe and a hot water flow passage of the pressure valve; the inlet pipe of the water heater and the cold water inlet end of the water mixing device are communicated with the cold water pipe through the cold runner of the pressure valve, so that hot water supplied by the water heater and cold water supplied by the cold water pipe can be mixed into water with appropriate temperature through the water mixing device, and the water is conveyed to a water outlet device (such as a shower head, a water faucet and the like) to be used by a user. Such a pressure valve does not have a water return function.

However, before the water supply system is turned on, a part of cold water remains in the end pipeline of the water supply system, and if the water supply system is turned on directly, the part of cold water is output to a user for use, that is, cold water is output at the initial stage of turning on the water supply system, which results in poor comfort of the water supply system.

Disclosure of Invention

The invention mainly aims to provide a water return valve, which aims to realize the water return function through the water return valve, return cold water remained in a tail end pipeline of a water supply system to a water heater through the water return valve, preheat the water heater and supply the water heater to a user, and reduce the output of cold water at the initial stage of starting the water supply system.

In order to achieve the purpose, the invention provides a water return valve, which comprises a valve body and a circulating valve; the valve body is provided with a hot runner, a cold runner and a circulating runner; a circulating inlet is arranged between the water inlet end and the water outlet end of the hot runner; a circulating outlet is arranged between the water inlet end and the water outlet end of the cold runner; the circulation flow channel is used for communicating the circulation inlet with the circulation outlet; the circulation valve is disposed in the circulation flow passage, and has an initial position closing the circulation inlet, and a circulation position opening the circulation inlet by a fluid pressure in the hot runner.

Optionally, the recirculation valve comprises a recirculation spool and a recirculation return; wherein the circulation valve core is arranged opposite to the circulation inlet; one end of the circulating reset piece is fixed in the circulating flow channel, and the other end of the circulating reset piece is connected with the circulating valve core.

Optionally, the hot runner includes a water inlet section, a water outlet section, and a communication section located between the water inlet section and the water outlet section, and the communication section is provided with a circulation inlet; the water return valve also comprises a linkage valve arranged in the hot runner; the linkage valve is provided with an initial position for blocking the communication section so that the water inlet section is not communicated with the water outlet section, and an opening position for communicating the communication section so that the water inlet section is communicated with the water outlet section.

Optionally, the communicating section is provided with a communicating inlet communicated with the water inlet section and a communicating outlet communicated with the water outlet section; the linkage valve comprises a linkage valve core and a switch resetting piece; the linkage valve core comprises a first blocking part arranged in the water outlet section and used for blocking the communication outlet, a second blocking part arranged in the communication section and used for blocking the communication inlet, and a linkage shaft connecting the first blocking part and the second blocking part; the switch resetting piece is arranged on the water outlet section and connected with the linkage valve core.

Optionally, the area of the blocking surface of the first blocking portion of the linkage valve element is larger than the area of the blocking surface of the second blocking portion.

Optionally, the linkage valve element further comprises a guide shaft coaxially arranged with the linkage shaft, and the guide shaft is connected to the blocking surface of the second blocking portion and is in insertion fit with the communication inlet.

Optionally, a plurality of water diversion grooves are formed in the circumferential wall of the guide shaft; the water diversion grooves are distributed at intervals along the periphery of the guide shaft, and extend to the plugging surface of the second plugging portion along the free end of the guide shaft.

Optionally, the outer peripheral surface of the first blocking portion is provided with a first sealing groove, a first sealing ring is arranged in the first sealing groove, and the outer peripheral surface of the first sealing ring is used for being in contact fit with the inner wall surface of the communication outlet.

Optionally, the water return valve further comprises a water outlet joint in insertion fit with the water outlet section of the hot runner, and a water outlet cavity communicated with the water outlet section is arranged at the inner end of the water outlet joint; the switch reset piece is at least partially installed in the water outlet cavity.

Optionally, the outer peripheral surface of the inner end of the water outlet joint is provided with a second sealing groove, a second sealing ring is arranged in the second sealing groove, and the outer peripheral surface of the second sealing ring is in contact fit with the inner wall surface of the water outlet section.

Optionally, the cold runner is further provided with a pressure relief inlet; the water inlet section of the hot runner is provided with a pressure relief outlet; the valve body still is equipped with the intercommunication the slow pressure export with the slow pressure runner of slow pressure entry, be provided with the slow pressure valve in the slow pressure runner, the slow pressure valve utensil is relevant to close the initial position of slow pressure entry, and open under the fluid pressure effect in the cold water runner the slow pressure position of slow pressure entry.

Optionally, the pressure relief valve comprises a damper spool and a damper reset member; the buffer valve core is arranged opposite to the pressure relief inlet; one end of the buffering reset piece is fixed in the pressure-relieving flow channel, and the other end of the buffering reset piece is connected with the buffering valve core.

Optionally, a pressure relief inlet is arranged at the water outlet section of the hot runner; the water inlet section of the hot runner is also provided with a pressure relief outlet; the valve body is also provided with a pressure relief flow channel for communicating the pressure relief outlet with the pressure relief inlet, a pressure relief valve is arranged in the pressure relief flow channel, the pressure relief valve is provided with an initial position for closing the pressure relief inlet, and a pressure relief position for opening the pressure relief inlet under the action of fluid pressure in the water outlet section.

Optionally, the valve body is also provided with a water passing flow channel; one end of the overflow channel is communicated with the pressure relief channel, and the other end of the overflow channel is communicated with the pressure relief outlet.

Optionally, the pressure relief valve comprises a pressure relief valve core and a pressure relief reset; the pressure relief valve core is arranged opposite to the pressure relief inlet; one end of the pressure relief resetting piece is fixed in the pressure relief flow channel, and the other end of the pressure relief resetting piece is connected with the pressure relief valve core.

Optionally, the tail end of the pressure relief flow passage is provided with an installation opening opposite to the pressure relief inlet; the pressure relief valve further comprises a pressure relief blocking cover for blocking the mounting opening, the pressure relief blocking cover is connected with one end, far away from the pressure relief inlet, of the pressure relief resetting piece, and the distance between the pressure relief blocking cover and the pressure relief inlet is adjustable.

Optionally, the valve body comprises a hot-flow side valve body, a cold-flow side valve body and a pipe portion; the hot flow side valve body is provided with the hot flow channel; the cold flow side valve body is provided with the cold runner; the piping part is used for forming at least one of a circulating flow passage, a pressure-relieving flow passage and a water passing flow passage;

one of the hot-flow side valve body and the cold-flow side valve body is integrally formed with one end of the pipe portion, and the other is connected to the other end of the pipe portion in a sealing manner.

Optionally, the hot-flow-side valve body is integrally formed with one end of the pipe portion, and an outer side surface of the cold-flow-side valve body is provided with an assembling portion hermetically connected with the pipe portion; or, the cold flow side valve body and one end of the pipe portion are integrally formed, and the outer side surface of the hot flow side valve body is provided with an assembling portion connected with the pipe portion in a sealing manner.

Optionally, the water return valve further comprises a pipe sealing ring, a fitting groove is formed in the free end face of the assembling portion or the pipe portion, and the pipe sealing ring is embedded in the fitting groove.

The invention also provides a water supply system, which comprises a water heater, a water mixing device and a water return valve; the water heater is provided with a water outlet pipe and a water inlet pipe; the heat flow inlet end and the cold flow inlet end of the water mixing device; the hot runner of the water return valve is used for communicating the heat flow access end of the water mixing device with the hot water pipe, and the cold runner of the water return valve is used for communicating the cold flow access end of the water mixing device with the water inlet pipe through a cold water pipe. The water return valve comprises a valve body and a circulating valve; the valve body is provided with a hot runner, a cold runner and a circulating runner; a circulating inlet is arranged between the water inlet end and the water outlet end of the hot runner; a circulating outlet is arranged between the water inlet end and the water outlet end of the cold runner; the circulation flow channel is used for communicating the circulation inlet with the circulation outlet; the circulation valve is disposed in the circulation flow passage, and has an initial position closing the circulation inlet, and a circulation position opening the circulation inlet by a fluid pressure in the hot runner.

Optionally, the water heater is a gas water heater or a gas wall-hanging stove or an electric water heater.

According to the technical scheme, a circulating inlet is arranged between a water inlet end and a water outlet end of a hot runner of a water return valve, a circulating outlet is arranged between a water inlet end and a water outlet end of a cold runner, a circulating flow passage for communicating the circulating inlet with the circulating outlet is arranged on a valve body, a circulating valve is arranged in the circulating flow passage, and the circulating valve has an initial position for closing the circulating inlet and a circulating position for opening the circulating inlet under the action of fluid pressure in the hot runner. By the design, the water return valve has a water return function, and when the zero cold water mode is started, cold water remained in a tail end pipeline of the water supply system can flow back to the water heater through the circulating flow channel of the water return valve to be preheated, so that the preheated water can be supplied to a user, and the condition that the water supply system outputs cold water at the initial starting stage is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic diagram of a unified embodiment of a water supply system according to the present invention;

FIG. 2 is a schematic structural diagram of a water return valve according to an embodiment of the present invention;

FIG. 3 is a schematic view of the water return valve of FIG. 2 from another perspective;

FIG. 4 is an exploded view of the water return valve of FIG. 2;

FIG. 5 is a schematic structural view of a hot side valve body of the water return valve of FIG. 4;

FIG. 6 is a schematic diagram of the cold flow side valve body of the water return valve of FIG. 4;

FIG. 7 is a top view of the water return valve of FIG. 4;

FIG. 8 is a cross-sectional view taken along line A-A of FIG. 7;

FIG. 9 is a cross-sectional view taken along line B-B of FIG. 7;

FIG. 10 is still another top view of the water return valve of FIG. 4;

FIG. 11 is a cross-sectional view taken along line C-C of FIG. 10;

FIG. 12 is a schematic view of the water flow path of the water return valve of FIG. 11 in a hot water mode;

FIG. 13 is a cross-sectional view taken along line D-D of FIG. 10;

FIG. 14 is a schematic view of the water flow path of the water return valve of FIG. 13 in a zero cold water mode;

FIG. 15 is a cross-sectional view taken along line E-E of FIG. 10;

FIG. 16 is a schematic view of the water return valve of FIG. 15 in a pressure relief mode;

FIG. 17 is a schematic structural diagram of a linkage valve of the water return valve according to an embodiment of the present invention;

FIG. 18 is a schematic view of a sealing member of the water return valve according to the present invention;

FIG. 19 is a schematic view of a water return valve according to the present invention;

FIG. 20 is a schematic view of the water flow path of the water return valve of the present invention in the cold water mode;

FIG. 21 is a schematic diagram of the water flow path of the water return valve of the present invention in a zero cold water mode;

FIG. 22 is a schematic view of the flow path of the return valve of the present invention in a pressure relief mode;

FIG. 23 is a schematic view of the flow path of the return valve of the present invention in a pressure relief mode;

FIG. 24 is a schematic structural view of a water supply system according to an embodiment of the present invention;

FIG. 25 is an exploded view of an embodiment of the water return valve of the present invention;

FIG. 26 is a schematic view of a portion of the internal structure of the assembled water return valve of FIG. 25;

FIG. 27 is a schematic view of the internal structure of the hot side valve body of FIG. 25 after assembly of the return valve;

FIG. 28 is a schematic view of the linkage valve of FIG. 27;

FIG. 29 is a schematic view of the seal ring of the piping in FIG. 25;

FIG. 30 is a schematic view of a water return valve according to the present invention;

FIG. 31 is a schematic view of the water flow path of the water return valve of the present invention in the cold water mode;

FIG. 32 is a schematic view of the water flow path of the water return valve of the present invention in a zero cold water mode;

FIG. 33 is a schematic view of the flow path of the return valve of the present invention in a pressure relief mode.

The reference numbers illustrate:

the implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that if the description of "first", "second", etc. is provided in the embodiment of the present invention, the description of "first", "second", etc. is only for descriptive purposes and is not to be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B" including either scheme A, or scheme B, or a scheme in which both A and B are satisfied.

In the related art, a water supply system is generally applied to supply hot and cold water to a user. The traditional water supply system generally comprises a water heater, a cold water pipe, a hot water pipe, a pressure valve, a water mixing device and other structures; the water outlet pipe of the water heater is connected with the hot water inlet end of the water mixing device through a hot water pipe and a hot water flow passage of the pressure valve; the inlet pipe of the water heater and the cold water inlet end of the water mixing device are communicated with the cold water pipe through the cold runner of the pressure valve, so that hot water supplied by the water heater and cold water supplied by the cold water pipe can be mixed into water with appropriate temperature through the water mixing device, and the water is conveyed to a water outlet device (such as a shower head, a water faucet and the like) to be used by a user. However, before the water supply system is turned on, a part of cold water remains in the end pipeline of the water supply system, and if the water supply system is turned on directly, the part of cold water is output to a user for use, that is, cold water is output at the initial stage of turning on the water supply system, which results in poor comfort of the water supply system.

In view of this, as shown in fig. 1 to 23, the present invention provides an embodiment of a water return valve, in which the water return valve 10 can replace a conventional pressure valve, and is intended to implement a water return function through the water return valve 10, so as to return cold water remaining in a terminal pipeline of a water supply system to a water heater 20 through the water return valve 10 to be preheated and then supplied to a user, thereby reducing cold water output at the initial stage of opening the water supply system.

Referring to fig. 2 to 4, in an embodiment of the water return valve of the present invention, the water return valve 10 includes a valve body 100 and a circulating valve 300, the valve body 100 is provided with a hot runner 101, a cold runner 102 and a circulating runner 103 (as shown in fig. 10 and 11); wherein, the hot runner 101 is provided with a circulating inlet 1031 between the water inlet end and the water outlet end thereof; the cold runner 102 is provided with a circulating outlet 1032 between the water inlet end and the water outlet end thereof; the circulation flow passage 103 communicates the circulation inlet 1031 with the circulation outlet 1032; a circulation valve 300 is provided in the circulation flow passage 103, the circulation valve 300 having an initial position closing the circulation inlet 1031 and a circulation position opening the circulation inlet 1031 by a fluid pressure in the hot runner 101.

As shown in fig. 1 and 3, the ends a and B are respectively shown as the water inlet end and the water outlet end of the hot runner 101 of the water return valve 10; the ends C and D are respectively indicated as the water inlet end and the water outlet end of the cold runner 102 of the water return valve 10. When the return valve 10 is assembled to the water supply system, the a end of the return valve 10 communicates with the outlet pipe 22 of the boiler 20 through the hot water pipe 50; the end B of the water return valve 10 is communicated with a heat flow inlet end 31 of the water mixing device 30; the end C of the return valve 10 is connected to a cold water source (e.g., a tap water line) via a cold water pipe 60, and the end D of the return valve 10 is connected to the cold fluid inlet 32 of the water mixing device 30. The water supply system at least has three working modes of a cold water mode, a hot water mode and a zero cold water mode by configuring the water return valve 10 into the water supply system. The operation principle of these three operation modes will be explained first.

Referring to fig. 20, when the water supply system uses the cold water mode, the cold water inlet 32 of the water mixing device 30 is in an open state, and the heat flow inlet 31 thereof is in a closed state; the cold water pipe 60 delivers cold water to the cold runner 102 of the water return valve 10, and then enters the water mixing device 30 through the cold water inlet 32 of the water mixing device 30, and finally is output to a water outlet structure (such as a shower head or a faucet) from the output end 33 of the water mixing device 30. In the process, the circulation valve 300 is kept at the initial position where the circulation inlet 1031 is closed, and the fluid in the cold runner 102 does not flow into the hot runner 101 from the circulation runner 103.

Referring to fig. 10 to 12, when the water supply system uses the hot water mode, the heat inflow end 31 of the water mixing device 30 is in an open state; the water heater 20 delivers hot water to the hot runner 101 of the water return valve 10 through the hot water pipe 50, then enters the water mixing device 30 through the hot water inlet 31 of the water mixing device 30, and finally is output to the water outlet structure from the output end 33 of the water mixing device 30. In the process, the pressure of the fluid in the hot runner 101 of the return valve 10 is lowered, the circulation valve 300 is still maintained at the position where the circulation inlet 1031 is closed, and the fluid in the hot runner 101 does not blow into the cold runner 102 from the circulation runner 103.

Referring to fig. 13, 14 and 21, when the water supply system uses the zero-cooling water mode, the output end 33 of the water mixing device 30 is closed, the water heater 20 is opened, the water heater 20 delivers hot water to the hot runner 101 of the water return valve 10 through the hot water pipe 50, and the output end 33 of the water mixing device 30 is closed, so that the fluid pressure in the hot runner 101 rises until the circulating valve 300 at the circulating inlet 1031 is pushed open by the fluid pressure in the hot runner 101, and the circulating valve 300 opens the circulating inlet 1031; in this manner, the fluid in the hot runner 101 can enter the circulation flow passage 103 through the circulation inlet 1031, then pass through the circulation flow passage 103, and enter the cold flow passage 102 of the water return valve 10 from the circulation outlet 1032; at this time, since the output end 33 of the water mixing device 30 is closed, the fluid entering the cold runner 102 can only reversely flow back to the water heater 20 through the cold water pipe 60, and is further heated by the water heater 20, thereby preheating the cold water remaining at the end of the water supply system. After preheating is finished, the hot water is supplied to the user.

In the technical scheme of the invention, a circulation inlet 1031 is arranged between a water inlet end and a water outlet end of a hot runner 101 of a water return valve 10, a circulation outlet 1032 is arranged between a water inlet end and a water outlet end of a cold runner 102, a circulation flow passage 103 for communicating the circulation inlet 1031 with the circulation outlet 1032 is arranged on a valve body 100, a circulation valve 300 is arranged in the circulation flow passage 103, and the circulation valve 300 has an initial position for closing the circulation inlet 1031 and a circulation position for opening the circulation inlet 1031 under the action of fluid pressure in the hot runner 101. Due to the design, the water return valve 10 has a water return function, and when the zero cold water mode is started, cold water remained in a tail end pipeline of the water supply system can flow back to the water heater 20 through the circulating flow channel 103 of the water return valve 10 to be preheated, so that the preheated water can be supplied to a user, and the condition that the water supply system outputs cold water at the initial starting stage is reduced.

Referring to fig. 4, 7 and 8, in an embodiment, for the circulation valve 300, the circulation valve 300 is a check valve, and the specific structure type of the check valve is not particularly limited. Optionally, recirculation valve 300 includes a recirculation spool 310 and a recirculation return 320; wherein the circulation valve core 310 is disposed opposite to the circulation inlet 1031; one end of the circulation returning member 320 is fixed in the circulation flow passage 103, and the other end thereof is connected to the circulation spool 310.

Specifically, when the circulation valve 300 is in its initial position, the circulation returning member 320 presses the circulation valve spool 310 against the circulation inlet 1031, so that the circulation valve spool 310 closes the circulation port. When the water supply system starts the zero-cold-water mode, the fluid pressure in the hot runner 101 of the water return valve 10 overcomes the elastic force of the circulation resetting piece 320, and the circulation valve core 310 is pushed open and moves in the direction away from the circulation inlet 1031, so that the circulation valve 300 is switched to the circulation position; at this time, the cyclic returning member 320 is compressed to accumulate elastic potential energy. Subsequently, when the water supply system is in the zero-cooling water mode, the fluid pressure in the hot runner 101 of the water return valve 10 is reduced, and the circulation resetting piece 320 releases the elastic potential energy to press and hold the circulation valve core 310 back to the initial position. As for the structural type of the circulating resetting member 320, the circulating resetting member 320 may be a spring, a spring plate, or other structure having restorability elasticity.

It is considered that when the water supply system uses cold water, the fluid pressure in the cold water pipe 60 is rapidly reduced when the cold water is turned on, so that the fluid pressure in the cold runner 102 of the return valve 10 is also suddenly reduced; at this time, because the hot runner 101 of the water return valve 10 is in the pressure maintaining state, the pressure of the fluid in the cold runner 102 of the water return valve 10 is suddenly reduced, so that the fluid in the hot runner 101 has a tendency of pushing the circulating valve 300 open at a moment, and therefore, the fluid in the hot runner 101 flows into the cold runner 102 through the circulating flow channel 103, and further, a flow signal occurs in the flow path of the hot water pipe 50, and the sensor of the water heater 20 detects the signal, which may cause the false start of the water heater 20.

Referring to fig. 8 and 9, in order to reduce the fluid in the hot runner 101 of the water return valve 10 from flowing into the cold runner 102 and to reduce the false start of the water heater 20 caused by the water flow signal in the flow path of the hot water pipe 50, in this embodiment, the hot runner 101 includes a water inlet section 1011, a water outlet section 1012 and a communication section 1013 located between the water inlet section 1011 and the water outlet section 1012, and the communication section 1013 is provided with a circulation inlet 1031; return valve 10 further includes a linkage valve 200 disposed within hot runner 101, linkage valve 200 being adapted to switch from an initial position to an open position when the pressure differential between water inlet section 1011 and water outlet section 1012 increases, wherein: when the linkage valve 200 is at the initial position, the linkage valve 200 blocks the communicating section 1013, so that the water inlet section 1011 and the water outlet section 1012 are not communicated; when the linkage valve 200 is in the open position, the linkage valve 200 connects the communicating section 1013 so that the water inlet section 1011 and the water outlet section 1012 are connected.

In particular, the linkage valve 200 is adapted to switch from an initial position to an open position when the pressure differential between the water inlet section 1011 and the water outlet section 1012 of the hot runner 101 increases; it has the following two meanings: 1) as soon as the difference between the water pressure in the water inlet section 1011 and the water pressure in the water outlet section 1012 begins to increase, the linkage valve 200 moves from the initial position to the open position; 2) when the difference between the water pressure in the water inlet section 1011 and the water pressure in the water outlet section 1012 increases to a predetermined value, the linkage valve 200 moves from the initial position to the open position. In the specific embodiment, the above two design modes can be selected according to actual requirements. As for the specific type of the linkage valve 200, the linkage valve 200 may be a valve structure having a switching function, such as a linkage valve or a one-way valve. As will be described in more detail below.

Therefore, when the water supply system uses cold water, when the cold water is turned on, the fluid pressure in the cold water pipe 60 is rapidly reduced, so that the fluid pressure in the cold runner 102 of the water return valve 10 is also rapidly reduced, because the water inlet section 1011 of the hot runner 101 of the water return valve 10 is connected with the hot water pipe 50, the pressure of the hot water pipe 50 is higher than that of the cold water pipe 60, the water flow in the hot water pipe 50 has a tendency of entering the cold runner 102 from the water inlet section 1011, and thus has a tendency of pushing the linkage valve 200 upwards; meanwhile, the water outlet section 1012 of the hot runner 101 is connected with the heat inlet end 31 of the water mixing device 30, the heat inlet end 31 is in a closed state, so the water outlet section 1012 is in a pressure maintaining state, and the pressure of the fluid in the cold runner 102 is reduced, so that the pressure difference is generated between the water outlet section 1012 of the hot runner 101 and the cold runner 102, and the water pressure of the water outlet section 1012 also has a tendency of pushing the linkage valve 200 downwards, so that the upward thrust of the water inlet section 1011 of the hot runner 101 on the linkage valve 200 is counteracted, the linkage valve 200 is limited from moving upwards and opening, and the linkage valve 200 is kept at an initial position. Therefore, the fluid in the water inlet section 1011 of the hot runner 101 does not enter the communicating section 1013, and the circulating valve 300 at the circulating inlet 1031 of the communicating section 1013 is not flushed away, so that the situation that the fluid in the hot runner 101 flows to the cold runner 102 through the circulating runner 103 can be reduced, a water flow signal is not easy to appear in the flow path of the hot water pipe 50, and a sensor of the water heater 20 is not easy to detect the water flow signal, so that the water heater 20 is not easy to be started by mistake.

When the water supply system uses the hot water mode, the heat flow inlet 31 of the water mixing device 30 is in an open state; the pressure of the water outlet section 1012 of the hot water channel 101 in the water return valve 10 is reduced and is reduced to be smaller than the pressure of the water inlet section 1011, so that the difference between the pressure in the water inlet section 1011 and the pressure in the water outlet section 1012 is increased, the linkage valve 200 is pushed upwards by the water flow of the water inlet section 1011, the linkage valve 200 moves to an open position, and the water flow of the hot water pipe 50 flows from the hot runner 101 to the water outlet section 1012 through the water inlet section 1011, enters the water mixing device 30 from the hot water inlet end 31 of the water mixing device 30, and is supplied to the water outlet device 40 through the outlet of the water mixing device 30. The flow rate of the hot water pipe 50 is increased, the sensor of the water heater 20 detects a water flow signal, and the water heater 20 is activated to prepare hot water.

When the water supply system uses the hot water mode, the output end 33 of the water mixing device 30 is in a closed state; the water heater 20 is started and pushes water flow to increase the water pressure of the hot water pipe 50, the pressure of the water inlet section 1011 of the hot water channel 101 in the water return valve 10 is increased, so that the linkage valve 200 is pushed to move upwards, when the linkage valve is static, the pressure of the water inlet section 1011 and the pressure of the water outlet section 1012 of the water return valve 10 are leveled, at the moment, the linkage valve 200 reaches an opening position, a large amount of water flow in the hot water pipe 50 enters the communicating section 1013, so that the circulating valve 300 is jacked to open against the acting force of the circulating resetting piece 320 of the circulating valve 300, the water flow enters the cold flow channel 102 through the circulating flow channel 103, and then the water flow returns to the water heater 20 from the cold flow channel 102 through the cold water pipe 60 for circulating heating.

Referring to fig. 4, 12 and 17, as for the structure type of the linkage valve 200, there are many structure design ways in the art. In the present embodiment, optionally, the communicating section 1013 is provided with a communicating inlet 10a communicating with the water inlet section 1011, and a communicating outlet 10b communicating with the water outlet section 1012; the linkage valve 200 comprises a linkage valve core 210 and a switch resetting piece 220; the linkage valve core 210 comprises a first blocking part 211 arranged in the water outlet section 1012 and used for blocking the communication outlet 10b, a second blocking part 212 arranged in the communication section 1013 and used for blocking the communication inlet 10a, and a linkage shaft 213 connecting the first blocking part 211 and the second blocking part 212; the switch resetting piece 220 is arranged on the water outlet section 1012 and is connected with the linkage valve core 210.

Specifically, when the linkage valve 200 is in the initial position, the second blocking portion 212 of the linkage spool 210 blocks the communication inlet 10a of the communication section 1013, and the first blocking portion 211 of the linkage spool 210 blocks the communication outlet 10b of the communication section 1013. When the linkage valve 200 is in the open position, the second blocking portion 212 of the linkage valve core 210 opens the communication inlet 10a of the communication section 1013, and the first blocking portion 211 opens the communication outlet 10 b. The switch reset member 220 may be a spring, a leaf spring, or other elastic structure having restorability. One end of the switch resetting piece 220 is fixedly connected with the inner wall of the hot runner 101, and the other end thereof is connected with the linkage valve core 210, so as to drive the linkage valve core 210 to switch from the open position to the initial position.

When the water supply system does not use hot water, the switch reset member 220 abuts the linkage spool 210 at the initial position, so that the linkage spool 210 simultaneously closes the communication inlet 10a and the communication outlet 10b of the communication section 1013. When hot water is used, the water pressure of the water inlet section 1011 of the hot runner 101 of the water return valve 10 is rapidly increased, and the water pressure of the water outlet section 1012 of the water return valve is rapidly decreased, so that the water in the water inlet section 1011 pushes the linkage valve core 210 to the water outlet section 1012, the first blocking part 211 and the second blocking part 212 of the linkage valve core 210 move in the same direction, and the communication inlet 10a and the communication outlet 10b of the communication section 1013 are both opened, so that the linkage valve 200 moves to be switched to the open position; in this process, the switch reset 220 accumulates elastic potential energy. After the hot water is used, the fluid pressure in the water inlet section 1011 of the hot runner 101 is reduced, the fluid pressure in the water outlet section 1012 is increased, and the linkage valve core 210 is restored to the initial position under the action of the elastic force released by the switch resetting piece 220.

It is considered that when the cold water is activated, the water pressure of the cold runner 102 is lowered, and the water of the cold runner 102 flows from the C end to the D end thereof; the water pressure stored in the hot water pipe 50 may be relatively high to slightly flush the linkage valve 200 and the circulation valve 300, so as to form a small gap from the hot runner 101 to the circulation flow channel 103, causing a part of the hot water in the hot water pipe 50 to flow from the small gap to the cold runner 102, thereby also causing the water heater 20 to be started by mistake. In view of this, to reduce this occurrence, it is optional that the plugging surface area of the second plugging portion 212 is larger than that of the first plugging portion 211. The plugging surface area shall mean an effective area for plugging the communication inlet 10a (or the communication outlet 10 b). Therefore, the fluid pressure required for flushing the linkage valve 200 can be increased, the linkage valve 200 is ensured not to be easily flushed by the water pressure stored in the hot water pipe 50 when cold water is used, and the situation that the water heater 20 is started by mistake due to hot water channeling caused by the cold water opening can be effectively reduced.

Further, the linkage valve core 210 further comprises a guide shaft 214 coaxially arranged with the linkage shaft 213, and the guide shaft 214 is connected to the blocking surface of the second blocking portion 212 and is inserted and matched with the communication inlet 10 a. Specifically, the diameter of the guide shaft 214 is smaller than or equal to the inner diameter of the communication inlet 10a, so that during the movement of the linkage spool 210, the guide shaft 214 can be kept inserted into the communication inlet 10a to guide the linkage spool 210 to move along the axial direction thereof, and the precise blocking of the communication inlet 10a and the communication outlet 10b by the linkage spool 210 is ensured. Optionally, the first blocking portion 211, the second blocking portion 212, the linkage shaft 213 and the guide shaft 214 of the linkage valve core 210 are integrally formed.

It is also considered herein that, with the guide shaft 214 remaining inserted in the communication inlet 10a, the linkage valve 200 is in the open position, the guide shaft 214 blocks part of the communication inlet 10a, so that part of the fluid in the water inlet section 1011 of the hot runner 101 is blocked by the guide shaft 214 and is not easily introduced into the communication section 1013. To improve this situation, optionally, the guiding shaft 214 is hollow, and a plurality of diversion grooves 214a are formed in a circumferential wall of the guiding shaft 214, and the diversion grooves 214a extend along a free end of the guiding shaft 214 to the blocking surface of the second blocking portion 212.

Specifically, the plurality of water diversion grooves 214a are arranged at intervals along the circumference of the guide shaft 214, each water diversion groove 214a extends to the plugging surface of the second plugging portion 212 along the free end of the guide shaft 214, so that the guide shaft 214 is divided into a plurality of water diversion ribs 214b, and one water diversion rib 214b is formed between every two adjacent water diversion grooves 214 a. With such an arrangement, when the linkage valve 200 is in the open position, the second blocking portion 212 of the linkage valve core 210 opens the communication inlet 10a, and the fluid in the water inlet section 1011 of the hot runner 101 can be guided into the communication section 1013 from the inside of the guide shaft 214 through the diversion trench 214a and the blocking surface of the second blocking portion 212, so that the blocking of the fluid by the guide shaft 214 is reduced, and the fluid in the water inlet section 1011 can smoothly enter the communication section 1013 through the communication inlet 10 a.

Alternatively, the first sealing groove 215 is provided on the outer peripheral surface of the first blocking portion 211, a first sealing ring 230 is provided in the first sealing groove 215, and the outer peripheral surface of the first sealing ring 230 is adapted to be in contact with the inner wall surface of the communication outlet 10 b. When the linkage valve 200 is in the initial position, the first sealing ring 230 is in contact fit with the inner wall surface of the communication outlet 10b, so that the sealing performance of the first blocking part 211 for blocking the communication outlet 10b is enhanced.

Referring to fig. 8, optionally, the water return valve 10 further includes a water outlet joint 600 installed at a water outlet end of the hot runner 101, and a water outlet cavity 610 communicated with the water outlet section 1012 is provided at an inner end of the water outlet joint 600; the switch reset 220 is at least partially disposed within the outlet chamber 610.

Specifically, the water outlet joint 600 is used for being connected with the hot water inlet 31 of the water mixing device 30, the water outlet cavity 610 of the water outlet joint 600 has a first cavity 611 and a second cavity 612 which are arranged along the water outlet direction of the water outlet joint, the inner diameter of the first cavity 611 is smaller than that of the second cavity 612, and thus a step surface 613 is formed between the first cavity 611 and the second cavity 612; one end of the switch resetting member 220 extends into the first cavity 611 and abuts against the step surface 613, and the other end of the switch resetting member 220 abuts against the first blocking portion 211 of the linkage valve core 210.

As for the connection manner of the water outlet joint 600 and the water outlet section 1012 of the hot runner 101, the two can be fixedly connected by screws or can be connected by threads. In order to improve the sealing performance of the joint between the water outlet joint and the water outlet section 1012, optionally, a second sealing groove 620 is provided on the outer circumferential surface of the inner end of the water outlet joint 600, a second sealing ring 630 is provided in the second sealing groove 620, and the outer circumferential surface of the second sealing ring 630 is in contact fit with the inner wall surface of the water outlet section 1012. In this way, the second sealing ring 630 can be used to seal the gap between the water outlet joint 600 and the water outlet section 1012 of the hot runner 101, so as to improve the sealing performance at the joint of the two.

It is also contemplated that after the water supply system uses chilled water, the fluid pressure within the chilled water pipe 60 will decrease, and the hot water pipe 50 will be slightly affected by this. Therefore, if the water pressure of the water pipes of some user residences is high, after the water supply system finishes using cold water, a water hammer effect is likely to occur when the cold water is turned off, so that the fluid pressure in the cold water pipe 60 rises suddenly, and the fluid pressure in the cold runner 102 of the water return valve 10 also rises suddenly, but the fluid pressure in the cold runner 102 rises but cannot enter the hot water pipe 50 from the circulation runner 103 through the hot runner 101 in the reverse direction, so that the fluid in the cold runner 102 flows back to the water heater 20 from the cold water pipe 60, and the water flow sensor 24 of the water heater 20 detects a water flow signal, which is likely to cause the false start of the water heater 20.

Referring to fig. 5 to 9, in an embodiment, to reduce the above situation, a pressure relief inlet 1041 is further disposed in the cold runner 102; a water inlet section 1011 of the hot runner 101 is provided with a pressure relief outlet 1042; the valve body 100 is further provided with a pressure relief flow passage 104 communicating with the pressure relief outlet 1042 and the pressure relief inlet 1041, a pressure relief valve 400 is arranged in the pressure relief flow passage 104, the pressure relief valve 400 has an initial position for closing the pressure relief inlet 1041 and a pressure relief position for opening the pressure relief inlet 1041 under the action of fluid pressure in the cold flow passage 102.

Specifically, the relief valve 400 is a one-way valve. As shown in fig. 19, when the water hammer effect occurs when the cold water is turned off, the water pressure in the cold water pipe 60 rises, and a part of the fluid in the cold runner 102 of the return valve 10 tends to flow back to the water heater 20 from the cold water pipe 60; meanwhile, a part of fluid in the cold flow passage 102 of the water return valve 10 has a tendency of pushing the pressure relief valve 400 open into the pressure relief flow passage 104, so that the fluid is transmitted to the water heater 20 through the pressure relief flow passage 104 and the hot water pipe 50, and thus a part of pressure flowing back from the cold water pipe 60 to the water heater 20 can be offset or at least offset, so that a water pressure difference between the water inlet pipe 21 and the water outlet pipe 22 of the water heater 20 can be weakened, and further a water flow signal on a flow path of the water heater 20 is weakened or not generated, and further the occurrence of false start of the water heater 20 can be reduced.

As for the relief valve 400, the relief valve 400 is a check valve, and the specific structural type of the check valve is not particularly limited. Optionally, the relief valve 400 includes a relief valve spool 410 and a relief reset 420; wherein, the pressure relief valve core 410 is arranged opposite to the pressure relief inlet 1041; one end of the pressure-relief resetting member 420 is fixed in the pressure-relief flow passage 104, and the other end thereof is connected to the pressure-relief valve spool 410.

In a normal case, the relief valve 400 is maintained at its initial position to close the relief inlet 1041. As shown in fig. 22, when the cold water used in the water supply system is finished and the water hammer effect occurs when the cold water is turned off, the water pressure in the cold water pipe 60 rises, the water pressure in the cold runner 102 of the return valve 10 pushes the pressure-reducing valve core 410 into the pressure-reducing runner 104, so that a part of the pressure in the cold water pipe 60 is transmitted to the hot water pipe 50 through the pressure-reducing runner 104, and at this time, the pressure-reducing reset piece 420 accumulates elastic force; meanwhile, the water flow in the hot water pipe 50 also has the tendency of reversely pushing the slow pressure valve 400 under the water hammer effect, so that the water pressure difference between the water inlet pipe 21 and the water outlet pipe 22 of the water heater 20 can be weakened, thereby avoiding the occurrence of more obvious water flow, also enabling the water flow signal to become weak, effectively avoiding the water flow sensor 24 of the water heater 20 from sensing the water flow signal, and further solving the problem of false start of the water heater 20. After the water hammer effect is over, the slow pressure resetting piece 420 releases the elastic potential energy and supports the slow pressure valve core 410 at the initial position for closing the slow pressure port.

It should be noted that, when cold water is used, the linkage valve 200 of the hot runner 101 is at the initial position, so that the communicating section 1013 of the hot runner 101 is also in a closed state, the water flow in the cold runner 102 is difficult to open the pressure relief valve 400, and the situation that the cold water flows to the hot water pipe 50 through the pressure relief runner 104 does not occur. When hot water is used, the communicating section 1013 of the hot runner 101 is pressurized at its initial position by a high water pressure, so that the hot water does not flow into the cold water pipe 60 through the pressure-reducing flow passage 104.

In one embodiment, considering that the water supply system is prone to water hammer effect when switching on and off cold water when the water pressure of the water line of the user's house is high, it may cause the water outlet section 1012 of the hot runner 101 of the water return valve 10 to maintain a higher pressure than the water inlet section 1011 thereof. This causes a greater pressure differential between the water outlet section 1012 and the water inlet section 1011 of hot runner 101, compressing linkage valve 200 in the initial position. When the zero-cold water mode is used subsequently, the water pressure of the water inlet section 1011 of the hot water channel 101 in the water return valve 10 is difficult to offset the pressure difference, and the linkage valve 200 is difficult to be pushed to be switched to the open position, so that the zero-cold water mode is difficult to be started.

Referring to fig. 5 to 9, in view of the above, in order to solve the above problem, optionally, the water outlet section 1012 of the hot runner 101 is provided with a pressure relief inlet 1051; the water inlet section 1011 of the hot runner 101 is also provided with a pressure relief outlet; the valve body 100 is further provided with a pressure relief flow channel 105 for communicating the pressure relief outlet and the pressure relief inlet 1051, a pressure relief valve 500 is arranged in the pressure relief flow channel 105, and the pressure relief valve 500 has an initial position for closing the pressure relief inlet 1051 and a pressure relief position for opening the pressure relief inlet 1051 under the action of fluid pressure in the water outlet section 1012.

The linkage valve 200 in the hot runner 101 of the return valve 10 is in the initial position before the water hammer effect occurs in the water supply system. As shown in fig. 15, 16 and 23, when the water hammer effect occurs in the switching of the cold water, the water pressure of the water outlet section 1012 of the hot runner 101 is suddenly increased, when the fluid pressure in the outlet section 1012 becomes too high, the fluid pressure in the outlet section 1012 will open the pressure relief valve 500, so that the relief valve 500 moves to the relief position, the relief valve 500 opens the relief inlet 1051, so that a small part of water in the water outlet section 1012 flows through the pressure relief flow channel 105 and the pressure relief outlet is discharged to the water inlet section 1011 of the hot runner 101, thereby realizing the pressure relief of the water outlet section 1012 to ensure that the pressure of the water outlet section 1012 is not too large, so as to balance the pressure difference between the water outlet section 1012 and the water inlet section 1011, thereby not only ensuring that the linkage valve 200 is maintained at the initial position at the moment, avoiding the water channeling problem after the cold water opening action is opened, but also ensuring that when the zero cold water mode is required to be opened subsequently, the linkage valve 200 can be easily opened, and the situation that the linkage valve 200 cannot be opened due to the fact that the pressure of the water outlet section 1012 is too high is avoided.

Due to the existence of the pressure relief valve 500, even if a water hammer phenomenon occurs when cold water is switched on and off in the cold water mode, the pressure in the water outlet section 1012 of the hot runner 101 is not too large. Therefore, after the zero-cold-water mode is started, the circulating water pump can push water flow to increase the pressure of the water inlet section 1011 of the water return valve 10, the pressure generated by the circulating water pump at the water inlet section 1011 of the water return valve 10 can better offset the pressure difference, the linkage valve 200 is further pushed to move upwards, the linkage valve 200 can be normally opened, and cold water circulation preheating at the tail end of the water supply system is realized. Therefore, the situation that the linkage valve 200 is difficult to normally open due to the fact that the linkage valve 200 is pressed at the initial position because the water outlet section 1012 of the hot water channel 101 in the water return valve 10 keeps high pressure after the zero-cold-water mode is started can be effectively reduced.

It can be understood that, if the water return valve 10 is provided with the pressure-relief outlet 1042 communicated with the pressure-relief flow channel 104 at the water inlet section 1011 of the hot runner 101, the pressure-relief outlet may be provided as the same opening as the pressure-relief outlet 1042, or may be provided as two separate openings as the pressure-relief outlet 1042. Specifically, in this embodiment, the pressure relief outlet and the pressure relief outlet 1042 are set to be the same opening.

Referring to fig. 5, 6 and 19, further, the valve body 100 is further provided with a water flow passage 106; one end of the overflow channel 106 is communicated with the pressure relief channel 105, and the other end of the overflow channel 106 is communicated with the pressure relief outlet. Specifically, since the pressure relief outlet and the pressure relief outlet 1042 are provided as the same opening, one end of the water passing flow channel 106, which is far away from the pressure relief flow channel 105, can be directly communicated with the pressure relief flow channel 104, and then communicated with the pressure relief outlet 1042 (i.e., the pressure relief outlet) through the pressure relief flow channel 104.

Referring to fig. 4, 15 and 16, for the pressure relief valve 500, the pressure relief valve 500 may have various structural design types. Optionally, relief valve 500 includes a relief spool 510 and a relief reset 520; wherein, the pressure relief valve core 510 is arranged opposite to the pressure relief inlet 1051; one end of the pressure relief reset piece 520 is fixed in the pressure relief flow passage 105, and the other end thereof is connected to the pressure relief valve core 510.

Specifically, when the relief valve 500 is in the initial position, the tension of the relief reset 520 presses the relief valve element 510 against the relief opening, so that the relief valve element 510 closes the relief inlet 1051; when the pressure of the fluid in the outlet section 1012 is greater than the tension of the pressure relief resetting member 520, the fluid in the outlet section 1012 pushes the pressure relief valve core 510 open, so that the pressure relief inlet 1051 is opened, and at this time, the pressure relief resetting member 520 is squeezed to accumulate elastic potential energy for driving the pressure relief valve core 510 to return to the initial position after the pressure relief is completed. The pressure release restoring member 520 is an elastic structure having elasticity, such as a spring, a leaf spring, etc.

In one embodiment, the fluid pressure maintained in the outlet section 1012 of the hot runner 101 is different after the cold water is turned on and off, thereby requiring different pressure relief levels in the outlet section 1012, taking into account the different water pressures in the water lines of the different user residences. For example, if the water pressure in the water line of some user residences is high, the fluid pressure in the outlet section 1012 of the hot runner 101 of the water return valve 10 is higher after the water supply system switches on and off the cold water.

In view of the above, in order to make the water return valve 10 applicable to the water pressure of the water pipes of different user houses, optionally, the end of the pressure relief flow passage 105 is provided with an installation port 1052 opposite to the pressure relief inlet 1051; the pressure relief valve 500 further includes a pressure relief cover 530 for closing the installation opening 1052, the pressure relief cover 530 is connected to an end of the pressure relief resetting member 520 far from the pressure relief inlet 1051, and a distance between the pressure relief cover 530 and the pressure relief inlet 1051 is adjustable.

Specifically, a pressure relief cap 530 is inserted into the mounting port 1052 to close off the mounting port 1052. Also, the pressure relief cap 530 is screw-coupled to an inner circumferential wall of the installation opening 1052, so that the pressure relief cap 530 can be rotated relative to the valve body 100 to adjust the depth of insertion into the installation opening 1052, thereby adjusting the distance between the pressure relief cap 530 and the pressure relief inlet 1051. Because the both ends of the pressure release reset piece 520 are respectively connected between the pressure release valve core 510 and the pressure release cap 530, therefore, the distance between the pressure release cap 530 and the pressure release inlet 1051 is adjusted, and the compression amount of the pressure release reset piece 520 extruded by the pressure release cap 530 can be adjusted, so that the pressure release reset piece 520 has different pressure release elasticity, and further the pressure release valve 500 has different pressure release values.

For example, increasing the depth of the pressure relief cap 530 extending into the installation opening 1052 can reduce the distance between the pressure relief cap 530 and the pressure relief inlet 1051, so that the compression degree of the pressure relief resetting member 520 is increased, which can make the pressure relief resetting member 520 have a larger pressure relief elastic force, and at this time, the water outlet section 1012 needs to have a higher water pressure to overcome the pressure relief elastic force of the pressure relief resetting member 520 to push the pressure relief valve core 510 open to the pressure relief position; and vice versa. Therefore, when the pressure of the waterway of the user's home is high, the distance between the pressure relief cap 530 and the pressure relief valve core 510 can be appropriately reduced. On the contrary, the distance between the pressure relief cap 530 and the pressure relief valve core 510 may be increased appropriately.

Referring to fig. 3 to fig. 6, based on any of the above embodiments, the valve body 100 of the water return valve 10 may be designed reasonably according to the flow rate of the flow channel and the position thereof, and is not limited herein. In one embodiment, the valve body 100 includes a hot-side valve body 110 and a cold-side valve body 120; wherein, the hot-flow side valve body 110 is provided with a hot-flow passage 101; the cold flow side valve body 120 is provided with a cold runner 102. The hot-flow side valve body 110 and the cold-flow side valve body 120 may be separately provided and then integrally connected. Of course, in other embodiments, the hot side valve body 110 and the cold side valve body 120 may be integrally formed.

In the present embodiment, the hot-flow side valve body 110 and the cold-flow side valve body 120 are separately provided and then integrally connected. Further, in view of the fact that the water return valve 10 may further be provided with any one or more of a circulation flow passage 103, a pressure-relief flow passage 104, a pressure-relief flow passage 105, and a water-passing flow passage 106, in order to facilitate the formation of these flow passages on the valve body 100 of the water return valve 10, optionally, the valve body 100 further includes a piping portion 130, and the piping portion 130 is configured to form at least one of the circulation flow passage 103, the pressure-relief flow passage 104, the pressure-relief flow passage 105, and the water-passing flow passage 106; one of the hot-side valve element 110 and the cold-side valve element 120 is integrally formed with one end of the pipe portion 130, and the other is hermetically connected to the other end of the pipe portion 130.

In one embodiment, the cold-side valve body 120 is integrally formed with one end of the pipe portion 130, and the outer side surface of the hot-side valve body 110 is provided with a fitting portion 140 that is sealingly connected to the pipe portion 130. With this arrangement, an opening that should communicate with the flow passage on the pipe portion 130 can be provided on the fitting portion 140 according to the specific type of flow passage formed on the pipe portion 130.

For example, if the circulation flow path 103 is provided in the pipe portion 130 of the cold flow side valve body 120, the circulation inlet 1031 communicating with the circulation flow path 103 is provided in the fitting portion 140 on the outer side of the hot flow side valve body 110; if the pipe portion 130 of the cold flow side valve body 120 is provided with the pressure relief flow passage 104, the fitting portion 140 outside the hot flow side valve body 110 is provided with a pressure relief outlet 1042 communicating with the pressure relief flow passage 104; if the relief flow passage 105 is provided in the pipe portion 130 of the cold flow side valve body 120, a relief inlet 1051 communicating with the relief flow passage 105 is provided in the mounting portion 140 outside the hot flow side valve body 110.

In another embodiment, the difference from the previous embodiment is that the hot-side valve body 110 is integrally formed with one end of the pipe portion 130, and the outer surface of the cold-side valve body 120 is provided with a fitting portion 140 that is hermetically connected to the pipe portion 130. Similarly, an opening that should communicate with the flow passage on the pipe portion 130 may be provided on the fitting portion 140 according to the type of the specific flow passage formed on the pipe portion 130.

For example, if the circulation flow path 103 is provided in the pipe portion 130 of the hot flow side valve body 110, the circulation outlet 1032 communicating with the circulation flow path 103 is provided in the fitting portion 140 outside the cold flow side valve body 120; if the relief flow passage 104 is provided in the pipe portion 130 of the hot flow side valve body 110, a relief inlet 1041 communicating with the relief flow passage 104 is provided in the fitting portion 140 outside the cold flow side valve body 120.

Further, in order to improve the sealing property of the connection between the pipe portion 130 and the fitting portion 140, the water return valve 10 further includes a pipe seal ring 700, a fitting groove 131 is provided on a free end surface of the fitting portion 140 or the pipe portion 130, and the pipe seal ring 700 is fitted into the fitting groove 131. The shape and structure of the pipe gasket 700 can be designed appropriately according to the number of openings in the mounting portion 140 and the shape thereof.

Here, description will be given taking as an example that the cold flow side valve body 120 is integrally molded with one end of the pipe portion 130, and the fitting portion 140 that is hermetically connected to the pipe portion 130 is provided on the outer side surface of the hot flow side valve body 110. Referring to fig. 5, 6 and 18, the pipe portion 130 of the cold flow side valve body 120 is provided with a circulation flow passage 103, a pressure relief flow passage 104 and a pressure relief flow passage 105, and the water flow passage 106 is formed on a free end surface of the pipe portion 130 and communicates the pressure relief flow passage 105 and the pressure relief flow passage 104. The mounting portion 140 of the heat flow side valve body 110 is formed with a circulation inlet 1031, a pressure relief outlet 1042, and a pressure relief inlet 1051. The piping seal ring 700 includes a first seal ring 710 surrounding the circulation inlet 1031, a second seal ring 720 surrounding the relief outlet 1042, and a third seal ring 730 surrounding the relief inlet 1051. The first seal ring 710, the second seal ring 720 and the third seal ring 730 are integrally connected. Wherein, the first sealing ring 710 is a complete ring body; the joint of the second sealing ring 720 and the third sealing ring 730 is provided with a joint part 740 arranged at an interval with the outer annular surface of the first sealing ring 710, and the joint part 740 and the outer annular surface of the first sealing ring 710 are matched to seal the water passing flow channel 106.

As for the manner of connecting and fixing the pipe portion 130 and the fitting portion 140, the pipe portion 130 and the fitting portion 140 may be connected and fixed by screwing. Of course, in other embodiments, a snap member may be provided on one of the pipe portion 130 and the fitting portion 140, and a mating member that is engaged with the snap member may be provided on the other, so that the pipe portion 130 and the fitting portion 140 may be connected and fixed by engaging the snap member with the mating member.

As shown in fig. 24 to 33, the present invention further provides an embodiment of a water return valve, which aims to solve the problem that it is difficult to open a linkage valve in a hot runner of the water return valve in a zero-cold-water mode of a water supply system.

Referring to fig. 24 to fig. 26, in an embodiment of the water return valve, the water return valve 10 includes a valve body 100, a linkage valve 200, a circulation valve 300, and a pressure relief valve 500. The valve body 100 is provided with a hot runner 101, a cold runner 102, a circulating runner 103 and a pressure relief runner 105; the hot runner 101 comprises a water inlet section 1011, a water outlet section 1012 and a communicating section 1013 positioned between the water inlet section 1011 and the water outlet section 1012; wherein, the water outlet section 1012 is provided with a pressure relief inlet 1051; the water inlet section 1011 is provided with a pressure relief outlet 1053 (shown in fig. 30); the communicating section 1013 is provided with a circulation inlet 1031; the cold runner is provided with a circulating outlet 1032; the circulation flow path 103 communicates the circulation inlet 1031 and the circulation outlet 1032; the relief flow passage 105 communicates the relief outlet 1053 and the relief inlet 1051. The linkage valve 200 is disposed in the hot runner 101 for adjusting the connection/disconnection of the communicating section 1013. The circulation valve 300 is disposed in the circulation flow passage 103 for opening and closing the circulation inlet 1031. The pressure relief valve 500 has an initial position closing the pressure relief inlet 1051 and a pressure relief position opening the pressure relief inlet 1051 under the pressure of the fluid in the outlet section 1012.

Specifically, the linkage valve 200 has an initial state of blocking the communicating section 1013 so that the water inlet section 1011 and the water outlet section 1012 are not communicated, and an open state of communicating the communicating section 1013 so that the water inlet section 1011 and the water outlet section 1012 are communicated. The linkage valve 200 is adapted to switch from an initial position to an open position when the pressure differential between the water inlet section 1011 and the water outlet section 1012 increases. The circulation valve 300 has an initial position closing the circulation inlet 1031 and a circulation position opening the circulation inlet 1031 by the action of the fluid pressure in the hot runner 101.

As shown in fig. 24 and 30, the ends a and B are respectively shown as the water inlet end and the water outlet end of the hot runner 101 of the water return valve 10; the ends C and D are respectively indicated as the water inlet end and the water outlet end of the cold runner 102 of the water return valve 10. When the return valve 10 is assembled to the water supply system, the a end of the return valve 10 communicates with the outlet pipe 22 of the boiler 20 through the hot water pipe 50; the end B of the water return valve 10 is communicated with a heat flow inlet end 31 of the water mixing device 30; the end C of the return valve 10 is connected to a cold water source (e.g., a tap water line) via a cold water pipe 60, and the end D of the return valve 10 is connected to the cold fluid inlet 32 of the water mixing device 30.

Referring to fig. 31, when the water supply system uses the cold water mode, the cold water inlet 32 of the water mixing device 30 is in an open state, and the heat inlet 31 thereof is in a closed state; the cold water pipe 60 delivers cold water to the cold runner 102 of the water return valve 10, and then enters the water mixing device 30 through the cold water inlet 32 of the water mixing device 30, and finally is output to a water outlet structure (such as a shower head or a faucet) from the output end 33 of the water mixing device 30.

When the water supply system uses the hot water mode, the heat flow inlet 31 of the water mixing device 30 is in an open state; the water heater 20 is turned on, the water heater 20 delivers hot water to the water inlet section 1011 of the hot runner 101 of the water return valve 10 through the hot water pipe 50, so that the fluid pressure in the water inlet section 1011 rises, the pressure difference between the water inlet section 1011 and the water outlet section 1012 increases, and the linkage valve 200 is pushed upward to switch the linkage valve 200 to the open position, so that the fluid in the water inlet section 1011 can enter the water mixing device 30 through the communicating section 1013, the water outlet section 1012 and the hot fluid inlet 3131 of the water mixing device 30, and finally the fluid is output to the water outlet structure from the output end 33 of the water mixing device 30. In the process, since the output end 33 of the mixing device 30 is opened, the fluid in the communicating section 1013 continues to flow to the output end 33 of the mixing device 30 through the water outlet section 1012 without flushing the pressure relief valve 500.

Referring to fig. 32, when the water supply system uses the zero-cold water mode, the output end 33 of the water mixing device 30 is closed, the water heater 20 is turned on, the water inlet pump 23 of the water heater 20 starts to work, and the water heater 20 delivers hot water to the water inlet section 1011 of the hot runner 101 of the water return valve 10 through the hot water pipe 50, so that the fluid pressure in the water inlet section 1011 rises to push the linkage valve 200 upward; when the fluid in the water inlet section 1011 enters the communicating section 1013 and the circulating valve 300 at the circulating inlet 1031 is pushed open by the communicating section 1013 after the output end 33 of the water mixing device 30 is closed, the circulating valve 300 opens the circulating inlet 1031; in this way, the fluid of the hot water pipe 50 can enter the circulation flow channel 103 through the water inlet section 1011, the communication section 1013, and the circulation inlet 1031 of the hot runner 101, then pass through the circulation flow channel 103, and enter the cold flow channel 102 of the water return valve 10 from the circulation outlet 1032; at this time, since the output end 33 of the water mixing device 30 is closed, the fluid entering the cold runner 102 can only reversely flow back to the water heater 20 through the cold water pipe 60 under the driving of the water inlet pump 23, and is further heated by the water heater 20, so that the cold water remaining at the end of the water supply system is preheated. After preheating is finished, the hot water is supplied to the user.

In the case of the conventional return valve with zero cold water, when the water pressure of the water pipeline of the user's house is high, the water supply system is prone to water hammer effect when the cold water is switched on and off (when the linkage valve 200 is in the initial position), which may cause the water outlet section 1012 of the hot runner 101 of the conventional return valve to maintain a higher pressure than the water inlet section 1011 thereof. This causes a greater pressure differential between the water outlet section 1012 and the water inlet section 1011 of hot runner 101, compressing linkage valve 200 in the initial position. When the zero-cold-water mode is used subsequently, the water outlet section 1012 of the hot runner 101 is in a pressure maintaining state, so that the pressure higher than the pressure of the water inlet section 1011 of the water outlet section 1012 is maintained in the water outlet section 1012, the pressure difference between the water inlet section 1011 of the hot runner 101 and the water outlet section 1012 is difficult to offset by the water pressure of the water inlet section 1011, the linkage valve 200 is difficult to push to switch to the opening position, and the zero-cold-water mode is difficult to open.

Referring to fig. 33, in the embodiment of the water return valve of the present invention, since the water return valve 10 is provided with the pressure relief flow channel 105 and the pressure relief valve 500 for opening and closing the pressure relief inlet 1051 of the pressure relief flow channel 105, if the water pressure of the water using pipeline of the user's house is higher, when the water hammer effect occurs during the cold water opening and closing process of the water supply system, once the water outlet section of the hot runner of the water return valve keeps higher pressure than the water inlet section thereof, the fluid pressure of the water outlet section 1012 pushes the pressure relief valve 500 open, so that the pressure relief valve 500 moves to the pressure relief position, the pressure relief inlet 1051 is opened by the pressure relief valve 500, so that a small amount of water in the water outlet section 1012 flows through the pressure relief flow channel 105 and the pressure relief outlet 1053 and is discharged to the water inlet section 1011 of the hot runner 101, thereby implementing the pressure relief to the water outlet section 1012 to ensure that the pressure of the water outlet section 1012 is not too high, balancing the pressure difference between the water outlet section 1012 and the water inlet section 1011, thereby greatly facilitating the easy opening of the linkage valve 200 when the subsequent water supply system starts the zero cold water mode, the situation that the linkage valve 200 cannot be opened due to the overlarge pressure of the water outlet section 1012 is avoided.

According to the technical scheme, a pressure relief inlet 1051 is arranged on a water outlet section 1012 of a hot runner 101 of a water return valve, a pressure relief outlet 1053 is further arranged on a water inlet section 1011 of the hot runner 101, the pressure relief outlet 1053 and the pressure relief inlet 1051 are communicated through a pressure relief flow channel 105, a pressure relief valve 500 is arranged on the pressure relief flow channel 105, the pressure relief valve 500 has an initial position for closing the pressure relief inlet 1051 and a pressure relief position for opening the pressure relief inlet 1051 under the action of fluid pressure in the water outlet section 1012, so that when the water hammer effect occurs in the process of switching cold water of the water supply system (at the initial position of a linkage valve 200), if the fluid pressure in the water outlet section 1012 is too high, the fluid pressure in the water outlet section 1012 pushes the pressure relief valve 500 open, so that the pressure relief inlet 1051 is opened by the pressure relief valve 500, a small amount of water in the water outlet section 1012 flows through the pressure relief flow channel 105 and the pressure relief outlet 1053 and is drained to the water inlet section 1011 of the hot runner 101, therefore, the pressure relief of the water outlet section 1012 is realized, the pressure of the water outlet section 1012 is ensured not to be too large, the pressure difference between the water outlet section 1012 and the water inlet section 1011 is balanced, the linkage valve 200 can be easily opened when the zero-cold-water mode of the water supply system is conveniently used subsequently, and the situation that the linkage valve 200 cannot be opened due to the fact that the pressure of the water outlet section 1012 is too large is avoided.

Referring to fig. 25, 26 and 33, in an embodiment, the valve body 100 is further provided with a water flow passage 106; one end of the water flow passage 106 is communicated with the pressure relief flow passage 105, and the other end of the water flow passage 106 is communicated with the pressure relief outlet 1053. Specifically, one end of the overflow channel 106 is communicated with one end of the pressure relief channel 105 close to the pressure relief inlet, so that when the pressure relief valve 500 moves a little distance, the pressure relief can be released to the water inlet section 1011 of the hot runner 101 through the overflow channel 106 and the pressure relief outlet 1053, and then the high pressure of the water outlet section 1012 of the hot runner 101 is discharged in time.

In any of the embodiments described above, the relief valve 500 is a one-way valve for the relief valve 500. The pressure relief valve 500 may be of a variety of structural design types. Optionally, relief valve 500 includes a relief spool 510 and a relief reset 520; wherein, the pressure relief valve core 510 is arranged opposite to the pressure relief inlet 1051; one end of the pressure relief reset piece 520 is fixed in the pressure relief flow passage 105, and the other end thereof is connected to the pressure relief valve core 510.

Specifically, when the relief valve 500 is in the initial position, the tension of the relief reset 520 holds the relief valve spool 510 against the relief inlet 1051, so that the relief valve spool 510 closes the relief inlet 1051; when the pressure of the fluid in the outlet section 1012 is greater than the tension of the pressure relief resetting member 520, the fluid in the outlet section 1012 pushes the pressure relief valve core 510 open, so that the pressure relief inlet 1051 is opened, and at this time, the pressure relief resetting member 520 is squeezed to accumulate elastic potential energy for driving the pressure relief valve core 510 to return to the initial position after the pressure relief is completed. The pressure release restoring member 520 is an elastic structure having elasticity, such as a spring, a leaf spring, etc.

Referring to fig. 25 and 26, in one embodiment, the fluid pressure in the outlet section 1012 of the hot runner 101 is different after the cold water is switched on and off, and therefore the pressure in the outlet section 1012 needs to be relieved to a different degree, considering the different water pressures in the water lines of different user residences. For example, if the water pressure in the water line of some user residences is high, the fluid pressure in the outlet section 1012 of the hot runner 101 of the water return valve 10 is higher after the water supply system switches on and off the cold water.

Specifically, a pressure relief cap 530 is inserted into the mounting port 1052 to close off the mounting port 1052. Also, the pressure relief cap 530 is screw-coupled to the inner peripheral wall of the installation hole 1052, so that the pressure relief cap 530 can be rotated with respect to the valve body 100 to adjust the depth of insertion into the pressure relief flow path 105, thereby adjusting the distance between the pressure relief cap 530 and the pressure relief inlet 1051. Because the both ends of the pressure release reset piece 520 are respectively connected between the pressure release valve core 510 and the pressure release cap 530, therefore, the distance between the pressure release cap 530 and the pressure release inlet 1051 is adjusted, and the compression amount of the pressure release reset piece 520 extruded by the pressure release cap 530 can be adjusted, so that the pressure release reset piece 520 has different pressure release elasticity, and further the pressure release valve 500 has different pressure release values.

For example, increasing the depth of the pressure relief cap 530 extending into the pressure relief flow channel 105 can decrease the distance between the pressure relief cap 530 and the pressure relief inlet 1051, so that the compression degree of the pressure relief resetting member 520 is increased, which can make the pressure relief resetting member 520 have a larger pressure relief elastic force, and at this time, the water outlet section 1012 needs a higher water pressure to overcome the pressure relief elastic force of the pressure relief resetting member 520, so as to push the pressure relief valve core 510 to the pressure relief position; and vice versa. Therefore, when the pressure of the waterway of the user's home is high, the distance between the pressure relief cap 530 and the pressure relief valve core 510 can be appropriately reduced. On the contrary, the distance between the pressure relief cap 530 and the pressure relief valve core 510 may be increased appropriately.

Referring to fig. 25, 27 and 28, there are many design ways in the art for the structure type of the linkage valve 200 according to any of the above embodiments. In the present embodiment, optionally, the communicating section 1013 is provided with a communicating inlet 10a communicating with the water inlet section 1011, and a communicating outlet 10b communicating with the water outlet section 1012; the linkage valve 200 comprises a linkage valve core 210 and a switch resetting piece 220; the linkage valve core 210 comprises a first blocking part 211 arranged in the water outlet section 1012 and used for blocking the communication outlet 10b, a second blocking part 212 arranged in the communication section 1013 and used for blocking the communication inlet 10a, and a linkage shaft 213 connecting the first blocking part 211 and the second blocking part 212; the switch resetting piece 220 is arranged on the water outlet section 1012 and is connected with the linkage valve core 210.

Referring to fig. 25 and 27, optionally, the water return valve 10 further includes a water outlet joint 600 installed at a water outlet end of the hot runner 101, and a water outlet cavity 610 communicated with the water outlet section 1012 is provided at an inner end of the water outlet joint 600; the switch reset 220 is at least partially disposed within the outlet chamber 610.

Referring to fig. 25 and 30, in any of the above embodiments, the circulation valve 300 is a check valve, and the specific structure type of the check valve is not particularly limited. Optionally, recirculation valve 300 includes a recirculation spool 310 and a recirculation return 320; wherein the circulation valve core 310 is disposed opposite to the circulation inlet 1031; one end of the circulation returning member 320 is fixed in the circulation flow passage 103, and the other end thereof is connected to the circulation spool 310.

Referring to fig. 25 and 26, based on any of the above embodiments, the valve body 100 of the water return valve 10 may be designed reasonably according to the flow rate of the flow channel and the position thereof, and is not limited herein. In one embodiment, the valve body 100 includes a hot-side valve body 110 and a cold-side valve body 120; wherein, the hot-flow side valve body 110 is provided with a hot-flow passage 101; the cold flow side valve body 120 is provided with a cold runner 102. The hot-flow side valve body 110 and the cold-flow side valve body 120 may be separately provided and then integrally connected. Of course, in other embodiments, the hot side valve body 110 and the cold side valve body 120 may be integrally formed.

In the present embodiment, the hot-flow side valve body 110 and the cold-flow side valve body 120 are separately provided and then integrally connected. Further, in view of the fact that the water return valve 10 may be further provided with any one or more of the pressure relief flow passage 105, the water passing flow passage 106 and the circulation flow passage 103, in order to facilitate the formation of these flow passages on the valve body 100 of the water return valve 10, optionally, the valve body 100 further includes a piping portion 130, and the piping portion 130 is configured to form at least one of the pressure relief flow passage 105, the water passing flow passage 106 and the circulation flow passage 103; one of the hot-side valve element 110 and the cold-side valve element 120 is integrally formed with one end of the pipe portion 130, and the other is hermetically connected to the other end of the pipe portion 130.

For example, if the relief flow passage 105 is provided in the pipe portion 130 of the cold flow side valve body 120, the relief inlet 1051 communicating with the relief flow passage 105 is provided in the mounting portion 140 outside the hot flow side valve body 110; if the circulation flow path 103 is provided in the pipe portion 130 of the cold flow side valve body 120, the circulation inlet 1031 communicating with the circulation flow path 103 is provided in the mounting portion 140 on the outer side of the hot flow side valve body 110.

In another embodiment, the difference from the previous embodiment is that the hot-side valve body 110 is integrally formed with one end of the pipe portion 130, and the outer surface of the cold-side valve body 120 is provided with a fitting portion 140 that is hermetically connected to the pipe portion 130.

Here, description will be given taking as an example that the cold flow side valve body 120 is integrally molded with one end of the pipe portion 130, and the fitting portion 140 that is hermetically connected to the pipe portion 130 is provided on the outer side surface of the hot flow side valve body 110. The piping portion 130 of the cold flow side valve body 120 is provided with a relief flow passage 105 and a circulation flow passage 103. The mounting portion 140 of the heat flow side valve body 110 is formed with a circulation inlet 1031, a relief inlet 1051, and a water flow passage 106.

The piping seal ring 700 includes a seal ring 710 and a seal rib 720; wherein, the sealing ring 710 is disposed in a ring shape and surrounds the outer circumference of the circulation inlet 1031; one end of the sealing rib 720 is connected to one side of the sealing ring 710, and the other end of the sealing rib 720 is connected to the other side of the sealing ring 710, so that the inner circumferential surface of the sealing rib 720 and the outer circumferential surface of the sealing ring 710 are fitted around the pressure relief inlet 1051 and the periphery of the water flow passage 106. The sealing ring 710 and the sealing rib 720 are integrally formed.

Referring to fig. 1 or 24, the present invention further provides a water supply system, which includes a water heater 20, a water mixing device 30 and a water return valve 10. Wherein, the water heater 20 is provided with a water outlet pipe 22 and a water inlet pipe 21; a hot inflow inlet 31 and a cold inflow inlet 32 of the water mixing device 30; the hot runner 101 of the water return valve 10 is used for communicating the hot fluid inlet 31 of the water mixing device 30 with the hot water pipe 50, and the cold runner 102 of the water return valve 10 is used for communicating the cold fluid inlet 32 of the water mixing device 30 with the water inlet pipe 21 through the cold water pipe 60. The specific structure of the return valve 10 refers to the above-described embodiment. Since the water supply system adopts all technical solutions of all the embodiments, all the beneficial effects brought by the technical solutions of the embodiments are also achieved, and are not repeated herein.

During assembly, the end A of the water return valve 10 is communicated with the water outlet pipe 22 of the water heater 20 through the hot water pipe 50; the end B of the water return valve 10 is communicated with a heat flow inlet end 31 of the water mixing device 30; the end C of the return valve 10 is connected to a cold water source (e.g., a tap water line) via a cold water pipe 60, and the end D of the return valve 10 is connected to the cold fluid inlet 32 of the water mixing device 30.

Optionally, the water supply system further comprises a water outlet device 40, and the water outlet device 40 is connected with the output end 33 of the water mixing device 30. The number of the water outlet means 40 may be one or two or more. When the number of the water discharge devices 40 is two or more, a water return valve 10 may be provided for each water discharge device 40, or a water return valve 10 may be provided only for the water discharge device 40 disposed at the farthest end. Of course, in other embodiments, the water outlet device 40 may be provided by the user.

As for the specific type of the water heater 20, the water heater 20 may be a gas water heater 20 or a gas wall-hanging stove or an electric water heater 20, and may be configured appropriately according to the market or the user's requirement, and is not limited specifically herein.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A water return valve, comprising:

the valve body is provided with a hot runner, a cold runner and a circulating runner; wherein, a circulating inlet is arranged between the water inlet end and the water outlet end of the hot runner; a circulating outlet is arranged between the water inlet end and the water outlet end of the cold runner; the circulation flow channel is used for communicating the circulation inlet with the circulation outlet; and

a circulation valve disposed within the circulation flow path, the circulation valve having an initial position closing the circulation inlet and a circulation position in which fluid pressure within the hot runner acts to open the circulation inlet.

2. The water return valve according to claim 1, wherein the circulation valve includes a circulation spool and a circulation returning member; wherein the circulation valve core is arranged opposite to the circulation inlet; one end of the circulating reset piece is fixed in the circulating flow channel, and the other end of the circulating reset piece is connected with the circulating valve core.

3. The water return valve according to claim 1, wherein the hot runner includes a water inlet section, a water outlet section, and a communication section between the water inlet section and the water outlet section, the communication section being provided with a circulation inlet; the water return valve also comprises a linkage valve arranged in the hot runner;

the linkage valve is provided with an initial position for blocking the communication section so that the water inlet section is not communicated with the water outlet section, and an opening position for communicating the communication section so that the water inlet section is communicated with the water outlet section.

4. The water return valve according to claim 3 wherein said communicating section is provided with a communicating inlet communicating with said water inlet section and a communicating outlet communicating with said water outlet section; the linkage valve comprises:

the linkage valve core comprises a first plugging part arranged in the water outlet section and used for plugging the communication outlet, a second plugging part arranged in the communication section and used for plugging the communication inlet, and a linkage shaft connecting the first plugging part and the second plugging part; and

and the switch resetting piece is arranged on the water outlet section and is connected with the linkage valve core.

5. The water return valve according to claim 4, wherein the area of the blocking surface of the first blocking portion of the linkage spool is larger than the area of the blocking surface of the second blocking portion.

6. The water return valve according to claim 4, wherein the linkage spool further includes a guide shaft disposed coaxially with the linkage shaft, the guide shaft being connected to the blocking surface of the second blocking portion and being in insertion engagement with the communication inlet.

7. The water return valve according to claim 6, wherein the circumferential wall of the guide shaft is provided with a plurality of water diversion grooves; the water diversion grooves are distributed at intervals along the periphery of the guide shaft, and extend to the plugging surface of the second plugging portion along the free end of the guide shaft.

8. The water return valve according to claim 4, wherein a first seal groove is provided in an outer peripheral surface of the first blocking portion, a first seal ring is provided in the first seal groove, and an outer peripheral surface of the first seal ring is adapted to be in contact engagement with an inner wall surface of the communication outlet.

9. The water return valve according to claim 4, further comprising a water outlet joint inserted into the water outlet section of the hot runner, wherein the inner end of the water outlet joint is provided with a water outlet cavity communicated with the water outlet section; the switch reset piece is at least partially installed in the water outlet cavity.

10. The water return valve according to claim 9, wherein a second sealing groove is provided on an outer circumferential surface of an inner end of the water outlet joint, a second sealing ring is provided in the second sealing groove, and an outer circumferential surface of the second sealing ring is in contact fit with an inner wall surface of the water outlet section.

11. The water return valve of claim 3 wherein said cold runner is further provided with a pressure relief inlet; the water inlet section of the hot runner is provided with a pressure relief outlet; the valve body is also provided with a pressure relief flow passage which communicates the pressure relief outlet with the pressure relief inlet; a pressure relief valve is arranged in the pressure relief flow passage;

the pressure relief valve is provided with an initial position for closing the pressure relief inlet and a pressure relief position for opening the pressure relief inlet under the action of fluid pressure in the cold water flow channel.

12. The water return valve according to claim 11 wherein the relief valve includes a relief valve spool and a relief return; the buffer valve core is arranged opposite to the pressure relief inlet; one end of the buffering reset piece is fixed in the pressure-relieving flow channel, and the other end of the buffering reset piece is connected with the buffering valve core.

13. The water return valve according to claim 3, wherein the water outlet section of the hot runner is provided with a pressure relief inlet; the water inlet section of the hot runner is also provided with a pressure relief outlet; the valve body is also provided with a pressure relief flow channel for communicating the pressure relief outlet with the pressure relief inlet, a pressure relief valve is arranged in the pressure relief flow channel, the pressure relief valve is provided with an initial position for closing the pressure relief inlet, and a pressure relief position for opening the pressure relief inlet under the action of fluid pressure in the water outlet section.

14. The water return valve of claim 13 wherein said valve body is further provided with a water passing flow passage; one end of the overflow channel is communicated with the pressure relief channel, and the other end of the overflow channel is communicated with the pressure relief outlet.

15. The water return valve of claim 13 wherein said pressure relief valve includes a pressure relief spool and a pressure relief reset; the pressure relief valve core is arranged opposite to the pressure relief inlet; one end of the pressure relief resetting piece is fixed in the pressure relief flow channel, and the other end of the pressure relief resetting piece is connected with the pressure relief valve core.

16. The water return valve according to claim 15 wherein a mounting opening is provided at a terminal end of the pressure relief flow passage opposite to the pressure relief inlet; the pressure relief valve further comprises a pressure relief blocking cover for blocking the mounting opening, the pressure relief blocking cover is connected with one end, far away from the pressure relief inlet, of the pressure relief resetting piece, and the distance between the pressure relief blocking cover and the pressure relief inlet is adjustable.

17. The water return valve according to any of claims 1 through 16 wherein said valve body includes a hot-flow-side valve body, a cold-flow-side valve body, and a pipe portion; the hot flow side valve body is provided with the hot flow channel; the cold flow side valve body is provided with the cold runner; the piping part is used for forming at least one of a circulating flow passage, a pressure-relieving flow passage and a water passing flow passage;

18. The water return valve according to claim 17 wherein said hot-flow-side valve body is formed integrally with one end of said pipe section, and an outer side surface of said cold-flow-side valve body is provided with a fitting portion to be sealingly connected to said pipe section; or, the cold flow side valve body and one end of the pipe portion are integrally formed, and the outer side surface of the hot flow side valve body is provided with an assembling portion connected with the pipe portion in a sealing manner.

19. The return valve according to claim 18, further comprising a pipe seal ring, wherein a fitting groove is provided on a free end surface of the fitting portion or the pipe portion, and the pipe seal ring is fitted into the fitting groove.

20. A water supply system, characterized in that the water supply system comprises:

a water heater having a water outlet pipe and a water inlet pipe;

the water mixing device comprises a heat flow incoming end and a cold flow incoming end of the water mixing device; and

the water return valve according to any one of claims 22 to 36, wherein a hot runner of the water return valve is used to communicate a hot inlet of the water mixing device with the hot water pipe, and a cold runner of the water return valve is used to communicate a cold inlet of the water mixing device with the inlet water pipe through a cold water pipe.

21. The water supply system of claim 20, wherein the water heater is a gas water heater or a gas wall-hanging stove or an electric water heater.

22. A water return valve, comprising:

the valve body is provided with a hot runner, a cold runner, a circulating runner and a pressure relief runner; the hot runner comprises a water inlet section, a water outlet section and a communication section for communicating the water inlet section and the water outlet section;

wherein the water outlet section is provided with a pressure relief inlet; the water inlet section is provided with a pressure relief outlet; the communicating section is provided with a circulating inlet, and the cold runner is provided with a circulating outlet; the circulating flow passage is communicated with the circulating inlet and the circulating outlet; the pressure relief flow passage is communicated with the pressure relief outlet and the pressure relief inlet;

the linkage valve is arranged on the hot runner and used for adjusting the connection and disconnection of the communication section;

the circulating valve is arranged in the circulating flow passage and used for opening and closing the circulating inlet; and

and the pressure relief valve is arranged in the pressure relief flow channel and is provided with an initial position for closing the pressure relief inlet and a pressure relief position for opening the pressure relief inlet under the action of fluid pressure in the water outlet section.

23. The water return valve of claim 22 wherein said valve body is further provided with a water flow passage; one end of the overflow channel is communicated with the pressure relief channel, and the other end of the overflow channel is communicated with the pressure relief outlet.

24. The water return valve of claim 23 wherein said pressure relief valve includes a pressure relief spool and a pressure relief reset; the pressure relief valve core is arranged opposite to the pressure relief inlet; one end of the pressure relief resetting piece is fixed in the pressure relief flow channel, and the other end of the pressure relief resetting piece is connected with the pressure relief valve core.

25. The water return valve according to claim 23 wherein a mounting opening is provided at a terminal end of the pressure relief flow passage opposite to the pressure relief inlet; the pressure relief valve further comprises a pressure relief blocking cover for blocking the mounting opening, the pressure relief blocking cover is connected with one end, far away from the pressure relief inlet, of the pressure relief resetting piece, and the distance between the pressure relief blocking cover and the pressure relief inlet is adjustable.

26. The water return valve according to any one of claims 22 through 25 wherein said communicating section is provided with a communicating inlet communicating with said water inlet section and a communicating outlet communicating with said water outlet section; the linkage valve comprises:

27. The water return valve according to claim 26, wherein a blocking surface area of the first blocking portion of the linkage spool is larger than a blocking surface area of the second blocking portion.

28. The water return valve according to claim 26 wherein the linkage spool further includes a guide shaft disposed coaxially with the linkage shaft, the guide shaft being connected to the blocking surface of the second blocking portion and being in insertion engagement with the communication inlet.

29. The water return valve according to claim 28 wherein the circumferential wall of the guide shaft is provided with a plurality of water diversion grooves; the water diversion grooves are distributed at intervals along the periphery of the guide shaft, and extend to the plugging surface of the second plugging portion along the free end of the guide shaft.

30. The water return valve according to claim 26, wherein an outer peripheral surface of the first blocking portion is provided with a first seal groove in which a first seal ring is provided, and an outer peripheral surface of the first seal ring is adapted to be in contact engagement with an inner wall surface of the communication outlet.

31. The water return valve according to claim 26, further comprising a water outlet joint inserted into the water outlet section of the hot runner, wherein an inner end of the water outlet joint is provided with a water outlet cavity communicated with the water outlet section; the switch reset piece is at least partially installed in the water outlet cavity.

32. The water return valve according to claim 31, wherein an outer peripheral surface of an inner end of the water outlet joint is provided with a second sealing groove, a second sealing ring is arranged in the second sealing groove, and an outer peripheral surface of the second sealing ring is in contact fit with an inner wall surface of the water outlet section.

33. The water return valve according to any of claims 22 through 25 wherein said circulation valve includes a circulation spool and a circulation return member; wherein the circulation valve core is arranged opposite to the circulation inlet; one end of the circulating reset piece is fixed in the circulating flow channel, and the other end of the circulating reset piece is connected with the circulating valve core.

34. The water return valve according to any of claims 22 through 25 wherein said valve body includes a hot-flow-side valve body, a cold-flow-side valve body, and a pipe portion; the hot flow side valve body is provided with the hot flow channel; the cold flow side valve body is provided with the cold runner; the piping part is used for forming at least one of a pressure relief flow passage, a circulation flow passage and a water passing flow passage;

35. The water return valve according to claim 34 wherein said hot-flow-side valve body is formed integrally with one end of said pipe section, and an outer side surface of said cold-flow-side valve body is provided with a fitting portion to be sealingly connected to said pipe section;

or, the cold flow side valve body and one end of the pipe portion are integrally formed, and the outer side surface of the hot flow side valve body is provided with an assembling portion connected with the pipe portion in a sealing manner.

36. The water return valve according to claim 35, further comprising a pipe seal ring, wherein a fitting groove is provided on a free end surface of said fitting portion or said pipe portion, and said pipe seal ring is fitted into said fitting groove.

37. A water supply system, characterized in that the water supply system comprises:

a water heater having a water outlet pipe and a water inlet pipe;

38. The water supply system of claim 37, wherein the water heater is a gas water heater or a gas wall-hanging stove or an electric water heater.