CN114484012A - Water return valve and water supply system - Google Patents

Abstract

The invention discloses a water return valve and a water supply system. The water return valve comprises a valve body, a one-way valve and a first elastic piece, the valve body is provided with a water channel, and the water channel comprises a first channel, a second channel and a third channel, wherein the first channel and the second channel are arranged at intervals, and the third channel is communicated with the first channel and the second channel; the one-way valve is used for guiding water in the first flow channel into the second flow channel in a one-way mode; the one-way valve is movably arranged in the waterway flow passage and blocks the third flow passage when in an initial position; the first elastic piece is used for enabling the one-way valve to have the tendency of resetting to the initial position; the check valve is used for leaving the initial position when the water pressure difference between the first flow passage and the second flow passage is increased to a preset pressure difference so as to open the third flow passage. Therefore, the water return valve is arranged in a water path of the water supply system, and a water return water path can be formed, so that the water supply system has a zero-cold-water function.

Description

Water return valve and water supply system

Technical Field

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

Background

The water supply system, such as a water supply system of a water heater or a water supply system of a wall-mounted boiler, is used for providing water for users, and generally comprises a gas heating device (such as a gas water heater or a wall-mounted boiler), a cold water pipe, a hot water pipe, a water mixing device and a water outlet end, wherein the water outlet end is connected with the gas heating device through the cold water pipe, the hot water pipe and the water mixing device.

In the related art, in order to make the water supply system have a zero cold water function, a return valve having a check valve is generally added to the water supply system, and the return valve is connected to a cold water pipe and a hot water pipe to form a return water path in the water supply system.

Disclosure of Invention

The invention mainly aims to provide a novel water return valve for forming a water return waterway in a water supply system.

In order to achieve the above object, the present invention provides a water return valve, including:

the valve body is provided with a waterway runner, and the waterway runner comprises a first runner, a second runner and a third runner, wherein the first runner and the second runner are arranged at intervals, and the third runner is communicated with the first runner and the second runner;

the check valve is used for guiding the water in the first flow channel into the second flow channel in a one-way mode; the one-way valve is movably arranged in the waterway flow passage and blocks the third flow passage when in an initial position; and

the first elastic piece is arranged in the waterway flow passage and used for enabling the one-way valve to have the tendency of resetting to the initial position;

the check valve is used for leaving the initial position when the water pressure difference between the first flow passage and the second flow passage is increased to a preset pressure difference so as to open the third flow passage.

Optionally, the check valve is movably installed in the third flow passage, and the first elastic member is disposed in the third flow passage;

the water return valve also comprises a temperature control component, the temperature control component comprises a temperature control driving component and an adjusting valve core, the adjusting valve core is positioned on the water outlet side of the one-way valve, and the adjusting valve core is movably arranged in the waterway flow channel in the direction far away from or close to the one-way valve;

the check valve is used for moving towards the direction close to the regulating valve core when the water pressure difference between the first flow passage and the second flow passage is increased to a preset pressure difference so as to open the third flow passage;

the temperature control driving assembly is arranged in the waterway runner and used for driving the regulating valve core to move towards the direction close to the one-way valve when the water temperature in the waterway runner rises to a preset temperature so as to drive the one-way valve away from the initial position to reset.

Optionally, when the check valve is in the initial position, an initial distance exists between the check valve and the regulating valve core, and the initial distance is smaller than the sum of the maximum movable distance of the regulating valve core and the maximum movable distance of the check valve and is greater than or equal to the maximum movable distance of the regulating valve core.

Optionally, the temperature control assembly further includes a valve core sleeve, the valve core is sleeved in the third flow passage, and the regulating valve core is movably arranged in the valve core sleeve;

the first elastic piece is a first spring, the first spring is sleeved outside the one-way valve, and two ends of the first spring are respectively arranged on the one-way valve and the valve core sleeve, so that the one-way valve has a tendency of resetting to the initial position.

Optionally, a first water passing structure is arranged on the valve core sleeve, and/or a second water passing structure is arranged on the regulating valve core, and/or a water passing gap is formed between the outer peripheral surface of the regulating valve core and the inner wall surface of the valve core sleeve.

Optionally, an inner support is disposed on an inner wall surface of the valve core sleeve, the inner support has a mounting through hole, one end of the regulating valve core is slidably mounted in the mounting through hole, and a first end of the first spring is disposed on the inner support.

Optionally, the temperature control driving assembly includes an ejector rod, a temperature sensing shell and a temperature sensing medium expanding when exposed to heat, the temperature sensing shell is located on the water outlet side of the one-way valve, the ejector rod is slidably mounted in the temperature sensing shell, and the adjusting valve core is mounted at the outer end of the ejector rod; the temperature sensing medium is arranged in the temperature sensing shell and is used for expanding when the temperature of water in the waterway flow passage rises to a preset temperature so as to enable the ejector rod to extend out, so that the regulating valve core is driven to move towards the direction close to the one-way valve; the temperature sensitive medium is also adapted to contract when cooled.

Optionally, the temperature control assembly further comprises a third elastic element, and the third elastic element is used for enabling the regulating valve core to have a resetting trend.

Optionally, the third elastic element is a third spring, the third spring is sleeved outside the adjusting valve core, and two ends of the third spring are respectively disposed on the inner support and the adjusting valve core, so that the adjusting valve core has a tendency of resetting.

Optionally, the adjusting valve core comprises a valve core main body and a limiting convex part convexly arranged on the peripheral surface of the valve core main body, an installation groove is formed in the end surface of one end of the valve core main body, and the outer end of the ejector rod is installed in the installation groove; two ends of the third spring are respectively arranged on the inner support and the limiting convex part, so that the adjusting valve core has a resetting trend; and the valve core main body is provided with a water through hole communicated with the mounting groove.

Optionally, the check valve includes a second elastic member, a valve housing, and a check valve element movably mounted in the valve housing, and both ends of the second elastic member are respectively disposed in the valve housing and the check valve element, so that the check valve element has a tendency to return to a closed position for closing the check valve; the first spring sleeve is arranged outside the valve shell, and two ends of the first spring are respectively arranged on the valve shell and the valve core sleeve, so that the one-way valve has the tendency of resetting to the initial position.

Optionally, a gear convex portion is convexly arranged on the outer circumferential surface of the valve housing, and the second end of the first spring is arranged on the gear convex portion.

Optionally, a sealing ring protrusion is formed on an inner wall surface of the third flow passage, and when the check valve is in the initial position, the gear protrusion abuts against the sealing ring protrusion.

Optionally, the check valve further includes a sealing ring, the sealing ring is installed on one side of the gear convex portion, which is far away from the adjusting valve core, and when the check valve is located at the initial position, the sealing ring is clamped between the sealing ring convex portion and the gear convex portion to block a third flow passage.

Optionally, the gear protrusions are distributed at intervals in the circumferential direction of the valve housing to open the third flow passage when the check valve leaves the initial position; or the gear convex part is an annular convex part, and a water through hole is formed in the gear convex part so as to open the third flow channel when the one-way valve leaves the initial position; and/or the presence of a gas in the gas,

a water passing gap is formed between the end face of the gear convex part and the inner wall face of the third flow channel, so that the third flow channel is opened when the one-way valve leaves the initial position.

The invention also proposes a water supply system comprising:

a gas heating device;

the water outlet end is connected with the gas water heater through a cold water pipe, a hot water pipe and a water mixing device; and

the water return valve has a first flow passage connected to the hot water pipe and a second flow passage connected to the cold water pipe.

Optionally, the gas heating device is a gas water heater or a gas wall-hanging stove.

The invention also proposes a water supply system comprising:

a gas heating device;

the water outlet end is connected with the gas water heater through a cold water pipe, a hot water pipe and a water mixing device;

the second flow passage of the water return valve is connected to the cold water pipe or the water inlet pipe of the fuel gas heating device; and

and one end of the water return pipe is connected to the hot water pipe, and the other end of the water return pipe is connected to the first flow channel of the water return valve.

In the invention, the water return valve is arranged in a water path of the water supply system and can form a water return water path, so that the water supply system has a zero cold water function; the problem that hot water in a hot water pipe or a return water pipe of a water supply system is easy to flow into a cold water pipe through a return valve when pressure is increased and hot water is delivered can be solved.

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 structural diagram of a unified embodiment of a water supply system according to the present invention;

FIG. 2 is a schematic structural view of another embodiment of the water supply system of the present invention;

FIG. 3 is a schematic structural diagram of a water return valve according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of the water return valve in FIG. 3 in a cold circulation state;

FIG. 5 is a schematic structural diagram of the water return valve in FIG. 3 in a hot circulation state;

FIG. 6 is a schematic structural diagram of the water return valve in FIG. 3 in a hot pressurized state;

FIG. 7 is an exploded schematic view of the water return valve of FIG. 3;

FIG. 8 is a schematic view of the check valve of FIG. 7;

fig. 9 is a schematic diagram of the regulator valve cartridge of fig. 7.

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.

The invention provides a water return valve and a water supply system.

As shown in fig. 1 and 2, the water return valve 100 is used in a water supply system 1000, that is, the water supply system 1000 includes the water return valve 100, so that the water supply system 1000 has a zero-cold-water function, so as to realize a timed cruise function and a heat preservation function. The water return valve 100 will be described in detail below with reference to the structure of a water supply system 1000, and optionally, the water supply system 1000 is a water supply system 1000 of a water heater (including but not limited to a gas water heater system) or a water supply system 1000 of a wall-hanging stove, etc., and the gas water heater system is taken as an example for description below.

In an embodiment of the present invention, as shown in fig. 1 and 2, the water supply system 1000 further includes a gas heating device 200, a cold water pipe 300, a hot water pipe 400, a water mixing device 600, a water outlet 700, a water return valve 100, and the like, wherein the water outlet 700 is connected to the gas heating device 200 through the cold water pipe 300, the hot water pipe 400, and the water mixing device 600; the return valve 100 is installed in a water path of the water supply system 1000 to form a return water path for providing the water supply system 1000 with a zero-cold water function.

Specifically, as shown in fig. 1 and 2, the gas heating device 200 has a cold water inlet 201 and a hot water outlet 202, and the water mixing device 600 has a hot water inlet, a cold water inlet, and a water mixing outlet.

Wherein, one end of the cold water pipe 300 and the cold water inlet 201 are both connected (i.e. communicated) with a water supply pipe (such as a tap water pipe, etc.), and the other end of the cold water pipe 300 is communicated with a cold water inlet; one end of the hot water pipe 400 is communicated with the hot water outlet 202, the other end is communicated with the hot water inlet, and the mixed water outlet is communicated with the water outlet end 700. Thus, the mixing device 600 can be adjusted to allow the outlet end 700 to deliver cold water alone or mixed hot water at an appropriate temperature.

Optionally, a cold water joint is arranged at the cold water inlet 201; and/or a hot water joint is arranged at the hot water outlet 202.

Optionally, the water supply system 1000 includes a water inlet pipe 210, the cold water inlet 201 is communicated with a water supply pipe through the water inlet pipe 210, and the cold water pipe 300 is communicated with the water inlet pipe 210.

Optionally, the water outlet end 700 may be a shower or a faucet.

Optionally, the water outlet end 700 may be provided in plurality.

Optionally, the mixing device 600 is a mixing valve or other mixing device 600 with similar function to the mixing valve.

Alternatively, the gas heating device 200 may be a gas water heater, a wall-mounted gas stove, or the like, and the following description will be given taking the gas water heater as an example.

In an embodiment of the present invention, as shown in fig. 3 to 9, the water return valve 100 includes a valve body 10, a check valve 20, and a first elastic member 50.

The valve body 10 has a waterway flow passage, and the waterway flow passage includes a first flow passage 11 and a second flow passage 12 which are arranged at intervals, and a third flow passage 13 which communicates the first flow passage 11 with the second flow passage 12.

Wherein the check valve 20 is used for guiding the water in the first flow passage 11 into the second flow passage 12 in a one-way manner; the check valve 20 is movably installed in the waterway flow passage, and the check valve 20 blocks the third flow passage 13 in an initial position.

Specifically, the check valve 20 is movably mounted in the third flow passage 13, so as to design and control the movement of the check valve 20. Of course, in other embodiments, the check valve 20 may be at least partially disposed in the third flow channel 13, that is, partially disposed in the third flow channel 13, and partially disposed in the first flow channel 11 or the second flow channel 12.

Wherein the first elastic element 50 is used to make the check valve 20 have a tendency to return to the initial position, so that the check valve 20 is always in the initial position. Specifically, the first elastic member 50 is disposed in the waterway flow passage.

Wherein the check valve 20 is used for leaving an initial position to open the third flow passage 13 when the water pressure difference between the first flow passage 11 and the second flow passage 12 increases to a preset pressure difference.

Specifically, the check valve 20 is a normally closed switch, and when the check valve 20 is closed, water in the first flow passage 11 cannot flow to the second flow passage 12 through the check valve 20; after the check valve 20 is opened, the water in the first flow passage 11 can pass through the check valve 20 so that the water in the first flow passage 11 can flow to the second flow passage 12.

It will be appreciated that when the check valve 20 is in the initial position and the check valve 20 is closed, the check valve 20 blocks the third flow passage 13 to prevent water in the first flow passage 11 from flowing to the second flow passage 12. However, when the check valve 20 is moved away from the initial position and/or the check valve 20 is opened, the third flow channel 13 is opened, and the water in the first flow channel 11 can flow to the second flow channel 12 through the third flow channel 13.

Specifically, the preset pressure difference may be greater than an opening threshold of the check valve 20 (i.e., a critical pressure value/pressure difference value for switching the check valve 20 from the closed state to the open state, in other words, when the water pressure difference in the first flow passage 11 and the second flow passage 12 increases to the opening threshold, the check valve 20 is opened), may also be smaller than the opening threshold of the check valve 20, and may also be equal to the opening threshold of the check valve 20. For example, the preset pressure difference may be made comparable to the opening threshold of the check valve 20, i.e., the preset pressure difference is slightly greater than, equal to, or slightly less than the opening threshold of the check valve 20. In this way, the non-return valve 20 can also be opened at the same time as the non-return valve 20 leaves the initial position.

The operation of the return valve 100 will be described in detail below with reference to the structure of the different water supply system 1000.

In an embodiment of the water supply system 1000, the water supply system 1000 is not provided with the water return pipe 500; as shown in fig. 1, the first flow passage 11 is connected to the heat exchange pipe, the second flow passage 12 is connected to the cold water pipe 300, and when the outlet end 700 has a plurality of flow passages, the return valve 100 is optionally provided at the most distal outlet end 700.

Specifically, one end (e.g., end B in the figure) of the first flow passage 11 is communicated with the hot water inlet through a hot water pipe 400, and the other end (e.g., end a in the figure) of the first flow passage 11 is communicated with the hot water outlet 202 through the hot water pipe 400; one end (e.g., end C in the drawing) of the second flow passage 12 is communicated with the cold water inlet through a cold water pipe 300, and the other end (e.g., end D in the drawing) of the second flow passage 12 is communicated with the water inlet pipe 210 through the cold water pipe 300. Thus, a backwater water path may be formed among the hot water pipe 400, the first flow path 11, the third flow path 13 and/or the fourth flow path, the second flow path 12, the cold water pipe 300, the water inlet pipe 210, the gas heating apparatus 200, and the like, and the backwater valve 100 may be disposed in the backwater water path.

Of course, the above water return valve 100 may also be used in the water supply system 1000 having the water return pipe 500. In another embodiment of the water supply system 1000 according to the present invention, as shown in fig. 2, the water supply system 1000 includes a water return pipe 500, one end of the water return pipe 500 is connected to the hot water pipe 400, the other end is connected to one end (e.g., end a) of the first flow passage 11, and the other end (e.g., end B) of the first flow passage 11 is blocked (e.g., by an end cap).

And in this embodiment, the second flow passage 12 is connected to the water inlet pipe 210 or the cold water pipe 300.

Alternatively, as shown in fig. 2, the second flow passage 12 is connected to the water inlet pipe 210; specifically, one end (e.g., end C in the drawing) of the second flow passage 12 is communicated with the cold water inlet 201 through the water inlet pipe 210, and the other end (e.g., end D in the drawing) of the second flow passage 12 is communicated with the cold water pipe 300 through the water inlet pipe 210.

Optionally, the water return valve 100 is disposed near the gas heating apparatus 200.

And in this embodiment, when the outlet end 700 has a plurality of parts, the water return pipe 500 is connected to the farthest outlet end 700.

Thus, a return water path may be formed between the hot water pipe 400, the return pipe 500, the first flow passage 11, the third flow passage 13 and/or the fourth flow passage, the second flow passage 12, the inlet pipe 210, and the heat exchanger of the gas heating apparatus 200, etc.; wherein the water return valve 100 is arranged in the water return waterway.

Specifically, for the above two embodiments, as shown in fig. 1 and 2, the gas heating apparatus 200 further includes a water circulating pump 800, the water circulating pump 800 is disposed in the water return waterway, and the water circulating pump 800 is configured to drive water to flow in the water return waterway. Optionally, the water circulation pump 800 is disposed between the heat exchanger of the gas heating apparatus 200 and the cold water inlet 201, so that the water circulation pump 800 can also be used for sucking cold water and/or pressurizing and delivering water, etc.

Specifically, when the water supply system 1000 in the above two embodiments performs the circulation preheating by using the zero cold water function, the circulation water pump 800 pushes water in the return water path to flow, so that the water pressure in the first flow channel 11 is increased, and thus the difference between the water pressure in the first flow channel 11 and the water pressure in the second flow channel 12 is increased; when the water pressure difference between the first flow passage 11 and the second flow passage 12 increases to a predetermined pressure difference (the predetermined pressure difference is equivalent to the opening threshold of the check valve 20, for example, described here), the check valve 20 leaves the initial position, and the check valve 20 opens, so that the water in the first flow passage 11 can flow into the second flow passage 12 through the third flow passage 13, so that the water circulates in the return water channel, and the water in the hot water pipe 400 and the like can be circularly preheated.

It can be understood that, after the cyclic preheating is completed, the circulating water pump 800 is turned off so that the water pressure in the hot water pipe 400 and the water pressure in the cold water pipe 300 gradually approach to equilibrium, and the check valve 20 is closed and is restored to the initial position by the first elastic member 50.

When the water outlet end 700 is used for boiling hot water and pressurizing (namely, pressurizing and delivering hot water), the circulating water pump 800 is used for pressurizing to increase the water outlet amount and the water outlet speed, and due to the characteristic curve of the water pump, when the water pump is just started, the water pressure in the first flow channel 11 is rapidly increased, so that the one-way valve 20 is separated from the initial position, and the one-way valve 20 is opened to cause water mixing; when the water outlet end 700 is opened for a period of time, that is, when the water flow rate of the water outlet end 700 is large, the pressure difference between the water inlet and the water outlet of the circulating water pump 800 is reduced, so that the check valve 20 is closed and reset to the initial position by adjusting the preset pressure difference and the opening threshold value of the check valve 20, for example, the water pressure difference between the first flow passage 11 and the second flow passage 12 does not reach the preset pressure difference and the opening threshold value of the check valve 20, so as to block the third flow passage 13, thereby preventing the hot water in the first flow passage 11 from flowing into the second flow passage 12 in series, and preventing the water from flowing in series when the hot water is pressurized, so as to prevent the gas heating device 200 from being started by mistake for preheating circulation and the like.

It should be noted that the preset pressure difference may be adjusted by adjusting the elastic parameter of the first elastic member 50 itself or the initial elastic value of the first elastic member 50 when the check valve 20 is at the initial position.

It should be noted that, when the preset differential pressure is smaller than the opening threshold of the check valve 20, there may be a case where the check valve 20 leaves the initial position to open the third flow passage 13 but the check valve 20 is not opened when the zero-cold-water function is used for the circulation warm-up.

It can be understood that, since the check valve 20 is movably disposed in the valve body 10 and the check valve 20 blocks the third flow passage 13 at the initial position, the first elastic member 50 makes the check valve 20 have a tendency to return to the initial position and leave the initial position when the difference between the water pressures in the first flow passage 11 and the second flow passage 12 increases to a preset pressure difference to open the third flow passage 13; a one-way normally closed switch structure can be formed between the one-way valve 20 and the third flow channel 13, so that the water return valve 100 has two normally closed switch structures which are connected in parallel and control the on-off of the third flow channel 13, and when the zero-cold-water function is used for circulating preheating, at least one of the two normally closed switch structures can be opened to ensure/increase the flow in the circulating water channel and increase/ensure the preheating speed.

In the invention, the water return valve 100 is installed in a water path of the water supply system 1000, and can form a water return water path, so that the water supply system 1000 has a zero cold water function; it is also possible to solve the problem that the hot water in the hot water pipe 400 or the return pipe 500 of the water supply system 1000 is easily flowed into the cold water pipe 300 through the return valve 100 when the hot water is pressurized and delivered.

In a further improvement of the present invention, a temperature control element 30 may be added to cooperate with the above two normally closed switch structures to improve the performance of the water return valve 100. The details will be described below.

Further, as shown in fig. 3 to 9, the check valve 20 is movably installed in the third flow passage 13, and the first elastic member 50 is provided in the third flow passage 13, so that the first elastic member 50 is designed.

Further, as shown in fig. 3 to 9, the water return valve 100 further includes a temperature control assembly 30, the temperature control assembly 30 includes an adjusting valve core 31, the adjusting valve core 31 is located at a water outlet side of the check valve 20, the adjusting valve core 31 is movably disposed in the waterway channel in a direction away from or close to the check valve 20, and the adjusting valve core 31 is configured to move in a direction close to the check valve 20 when the temperature of the water in the valve body 10 rises to a preset temperature.

Further, as shown in fig. 3 to 9, the check valve 20 is configured to move toward the direction approaching the regulator valve body 31 when the water pressure difference between the first flow passage 11 and the second flow passage 12 increases to a predetermined pressure difference, so as to open the third flow passage 13.

Further, as shown in fig. 3 to 9, the regulating valve core 31 is configured to move toward the check valve 20 when the temperature of the water in the valve body 10 rises to a preset temperature, so as to drive the check valve 20 away from the initial position to reset.

Specifically, as shown in fig. 3 to 9, the temperature control assembly 30 further includes a temperature control driving assembly 32, the temperature control driving assembly 32 is installed in the water path channel, and the temperature control driving assembly 32 is configured to drive the regulating valve core 31 to move toward the direction close to the check valve 20 when the temperature of the water in the water path channel rises to a preset temperature.

Specifically, when the check valve 20 is in the initial position, an initial distance is formed between the check valve 20 and the regulating valve core 31, and the initial distance is smaller than the sum of the maximum movable distance of the regulating valve core 31 and the maximum movable distance of the check valve 20 and is greater than or equal to the maximum movable distance of the regulating valve core 31.

Specifically, the check valve 20 moves to the movement locus of the regulator valve body 31 when moving in a direction approaching the regulator valve body 31. When the initial distance is smaller than the sum of the maximum movable distance of the adjustment spool 31 and the maximum movable distance of the check valve 20 and is greater than or equal to the maximum movable distance of the adjustment spool 31, the check valve 20 moved to the movement locus of the adjustment spool 31 is driven to move in the direction returning to the initial position when the adjustment spool 31 moves in the direction approaching the check valve 20.

Alternatively, the initial distance is equal to the maximum movable distance of the regulator spool 31, so that the regulator spool 31 drives the check valve 20 to return to the initial position when moving in a direction to approach the check valve 20.

Specifically, as shown in fig. 4, when the water supply system 1000 in the above two embodiments performs the circulation preheating by using the zero cold water function, the circulation water pump 800 pushes water in the return water path to flow, so that the water pressure in the first flow channel 11 is increased, and thus the difference between the water pressure in the first flow channel 11 and the water pressure in the second flow channel 12 is increased; when the water pressure difference between the first flow channel 11 and the second flow channel 12 increases to a predetermined pressure difference (the predetermined pressure difference is smaller than the opening threshold of the check valve 20, for example, described here), the check valve 20 moves toward the direction of the regulating valve core 31 and moves away from the initial position to open the third flow channel 13, but the check valve 20 is not opened, so that the water in the first flow channel 11 can flow into the second flow channel 12 through the third flow channel 13, so that the water circulates in the return water channel, and the water in the hot water pipe 400 and the like can be circularly preheated. At this time, as shown in fig. 4, the return valve 100 is in a cold circulation state, and the check valve 20 is located on the moving track of the adjustment spool 31.

Referring to fig. 5, when the temperature of the water in the hot water pipe 400 or the water return pipe 500 rises to a certain temperature but does not reach the expected preheating temperature (such as 100), and the temperature of the water in the water path channel (specifically, at the temperature control element 30) rises to a preset temperature, the regulating valve core 31 moves toward the check valve 20, and since the initial distance is smaller than the sum of the maximum movable distance of the regulating valve core 31 and the maximum movable distance of the check valve 20 and is greater than or equal to the maximum movable distance of the regulating valve core 31, and the check valve 20 is located on the moving track of the regulating valve core 31, the regulating valve core 31 abuts against the check valve 20 during the moving process, and drives the check valve 20 moving to the moving track of the regulating valve core 31 to move toward the initial position.

It is understood that if the initial distance is equal to the maximum movable distance of the regulating spool 31, the regulating spool 31 may drive the check valve 20 to return to the initial position to block the third flow passage 13; however, because the preset preheating temperature is not reached, the circulation preheating is not finished, and the water circulating pump 800 still pushes water in the water returning waterway to flow, so that the water pressure difference between the first flow passage 11 and the second flow passage 12 is continuously increased until the check valve 20 is opened to open the third flow passage 13, so that the water continuously circularly flows in the water returning waterway to continuously circularly preheat until the preset preheating temperature is reached. At this time, as shown in fig. 5, the return valve 100 is in a thermal cycle state.

The description will be continued by taking as an example the initial distance equal to the maximum movable distance of the regulator spool 31.

As shown in fig. 6, when the outlet end 700 is heated and pressurized (i.e., hot water is pressurized), the circulating water pump 800 is used to pressurize to increase the outlet amount and the outlet speed, and due to the characteristic curve of the water pump, when the water pump is just turned on, the water pressure in the first flow channel 11 is rapidly increased, so that the check valve 20 is moved away from the initial position or the check valve 20 is opened, causing water leakage.

It will be appreciated that when the outlet end 700 is hot and pressurized (i.e., pressurized to deliver hot water), there are two situations, one where hot water is present in the hot water pipe 400 and the other where cold water is present in the hot water pipe 400.

For the case of cold water in the hot water pipe 400, when the water pump is just started, the water pressure in the first flow channel 11 will increase rapidly, so that the check valve 20 leaves the initial position, causing water leakage; when the hot water reaches the return valve 100 after being opened for a while, the regulating valve core 31 moves towards the direction close to the one-way valve 20 to drive the one-way valve 20 moving to the moving track of the regulating valve core 31 to reset to the initial position; at this time, when the water flow rate of the water outlet 700 is large, the pressure difference between the water inlet and the water outlet of the circulating water pump 800 is reduced, which is not enough to open the check valve 20, so that the third flow passage 13 is blocked, thereby preventing the hot water in the first flow passage 11 from flowing into the second flow passage 12, that is, preventing water leakage when the hot water is pressurized and delivered, and preventing the gas heating apparatus 200 from being started by mistake to perform a preheating cycle or the like. At this time, as shown in fig. 6, the return valve 100 is in the hot state pressurized state.

In the case that the hot water is in the hot water pipe 400, the hot water is also in the water return valve 100 communicated with the hot water pipe 400, that is, the regulating valve core 31 is in a state of abutting against the check valve 20 to be fixed at the initial position, in this case, when the water pump is just started, the water pressure in the first flow passage 11 is rapidly increased, so that the check valve 20 is opened, and water mixing is caused; when the water outlet end 700 is opened for a period of time, because the water flow rate of the water outlet end 700 is large, the pressure difference of the water inlet and the water outlet of the circulating water pump 800 is reduced, the check valve 20 is closed, and the third flow passage 13 is blocked, so that the hot water in the first flow passage 11 can be prevented from flowing into the second flow passage 12 in series, namely, the effect of preventing water from flowing in series when the pressure is increased to deliver the hot water is realized.

That is, at the time of design, the effect of preventing water breakthrough at the time of increasing the pressure of the hot water can be achieved by increasing the opening threshold of the check valve 20.

Further, as shown in fig. 3 to 9, the check valve 20 includes a second elastic member 23, a valve housing 22, and a check valve core 21, and the check valve core 21 is movably installed in the valve housing 22 to realize opening or closing of the check valve 20.

Specifically, the check valve body 21 has a closed position for closing the check valve 20, and both ends of the second elastic member 23 are respectively disposed in the valve housing 22 and the check valve body 21, so that the check valve body 21 has a tendency to return to the closed position for closing the check valve 20. Wherein the first spring 50 acts on the valve housing 22 to give the check valve spool 21 a tendency to return to a closed position closing the check valve 20.

It will be appreciated that the opening threshold of the second elastic element 23 can be adjusted by adjusting its own elastic parameter or the initial elastic value of the second elastic element 23 when the non-return valve spool 21 is in the closed position.

Further, as shown in fig. 3 to 9, the temperature control assembly 30 further includes a valve core sleeve 36, the valve core sleeve 36 is disposed in the third flow channel 13, and the regulator valve core 31 is movably disposed in the valve core sleeve 36.

Specifically, the valve core sleeve 36 is fixedly installed in the third flow channel 13, and the regulating valve core 31 is slidably disposed in the valve core sleeve 36.

Further, as shown in fig. 3 to 9, two ends of the first elastic element 50 are respectively disposed on the check valve 20 and the valve core sleeve 36, so that the check valve 20 has a tendency to return to the initial position.

Specifically, as shown in fig. 3 to 9, the first elastic element 50 is a first spring, the first spring is sleeved outside the check valve 20, and two ends of the first spring are respectively disposed on the check valve 20 and the valve core sleeve 36, so that the check valve 20 has a tendency of returning to the initial position. Thus, the structure can be simplified conveniently, and the performance of the spring is more stable, thereby improving the reliability.

Of course, in other embodiments, the first elastic member 50 may be provided with other elastic members such as an elastic pressing sheet, a rubber band, or a pressing band.

In a specific embodiment, in order to prevent the valve core sleeve 36 and the regulator valve core 31 from blocking the third flow channel 13, a first water passing structure may be provided on the valve core sleeve 36, and/or a second water passing structure may be provided on the regulator valve core 31, and/or a water passing gap may be formed between an outer circumferential surface of the regulator valve core 31 and an inner wall surface of the valve core sleeve 36, and/or a through flow gap may be provided between an inner wall surface of the third flow channel 13 and the valve core sleeve 36, and so on. The second water passing structure provided on the regulating valve core 31 will be described as an example.

Further, an inner support 361 is arranged on the inner wall surface of the valve core sleeve 36, the inner support 361 has a mounting through hole 3611, one end of the regulating valve core 31 is slidably mounted in the mounting through hole 3611, and a first end of the first spring is arranged on the inner support 361.

Specifically, a first end of the first spring abuts against the inner support 361.

In this way, on the one hand, the stability of the movement of the control valve disk 31 can be increased, and on the other hand, the arrangement of the first spring is also facilitated.

It will be appreciated that the inner support 361 has water passing holes.

Further, as shown in fig. 3-9, the check valve 20 abuts one end of the regulator spool 31 or the inner support 361 at the maximum displacement position. In this way, the movement of the check valve 20 in the direction approaching the regulator valve body 31 can be restricted.

Further, as shown in fig. 3 to 9, the first spring is sleeved outside the valve housing 22, and two ends of the first spring are respectively disposed on the valve housing 22 and the valve core sleeve 36, so that the check valve 20 has a tendency to return to the initial position.

In this way, not only the movement stability of the check valve 20 can be improved, but also the space occupied in the movement direction of the check valve 20 can be reduced. In addition, the adjustment valve core 31 can drive the valve shell 22 to move conveniently.

Further, as shown in fig. 3 to 9, a gear protrusion 221 is protruded on the outer circumferential surface of the valve housing 22, and the second end of the first spring is disposed on the gear protrusion 221. Specifically, the second end of the first spring abuts against the gear protrusion 221.

Thus, the two elastic ends of the first spring are respectively abutted against the convex part 221 and the inner support 361, so that the first spring is in a compressed state, and the check valve 20 has a tendency of returning to the initial position.

Further, as shown in fig. 3 to 9, a sealing ring protrusion 131 is formed on an inner wall surface of the third flow passage 13, and the shift protrusion 221 abuts against the sealing ring protrusion 131 when the check valve 20 is at the initial position. In this way, the check valve 20 can be restrained at the initial position.

Further, as shown in fig. 3 to 9, the check valve 20 further includes a sealing ring 24, the sealing ring 24 is installed on a side of the shift protrusion 221 away from the regulating valve core 31, and when the check valve 20 is in the initial position, the sealing ring 24 is interposed between the sealing ring protrusion 131 and the shift protrusion 221 to block the third flow channel 13.

Alternatively, the gear protrusion 221 is provided at an end of the valve housing 22 away from the regulator valve core 31.

Further, as shown in fig. 3 to 9, the gear protrusions 221 are distributed at intervals in the circumferential direction of the valve housing 22 to open the third flow passages 13 when the check valve 20 leaves the initial position; or, the gear convex part 221 is an annular convex part, and a water through hole is formed in the gear convex part 221 so as to open the third flow channel 13 when the check valve 20 leaves the initial position; and/or the presence of a gas in the gas,

a water passing gap is provided between an end surface of the shift protrusion 221 and an inner wall surface of the third flow passage 13, so as to open the third flow passage 13 when the check valve 20 is away from the initial position.

In this way, it is achieved that the third flow channel 13 is opened when the non-return valve 20 leaves the initial position.

In this embodiment, the plurality of gear protrusions 221 are spaced apart from each other in the circumferential direction of the valve housing 22, a water passing space is formed between two adjacent gear protrusions 221, and an annular protrusion formed by the plurality of gear protrusions 221 is slidably installed in the third flow channel 13 to improve the movement stability of the valve housing 22.

Of course, in other embodiments, a sealing convex portion may be protruded on the circumferential surface of the valve housing 22 and on the side of the gear convex portion 221 away from the adjustment valve core 31 to be matched with the sealing ring convex 131.

Further, as shown in fig. 3-9, the valve housing 22 includes a housing body and a valve cover, the check valve core 21 includes a valve core head and a valve core guide post connected to the valve core head, a limit step is convexly disposed on an inner wall surface of the housing body, and when the check valve core 21 is in a closed position, the valve core head abuts against the limit step; the valve cover is provided with a water passing structure and a guide hole, and the valve core guide post is slidably arranged in the guide hole.

The second elastic element 23 is a second spring, the second spring is sleeved outside the valve core guide post, and two ends of the second spring are respectively abutted against the valve core head and the valve cover.

Specifically, the adjustment spool 31 is used for valve cover abutment to drive the valve housing 22 and the check valve 20 to move.

Specifically, the initial distance is a distance between the bonnet and the adjustment valve core 31 in a moving direction of the adjustment valve core 31.

Further, as shown in fig. 3 to 9, the temperature control driving assembly 32 includes a top rod 321, a temperature sensing shell 322 and a temperature sensing medium 323 expanding when exposed to heat, the temperature sensing shell 322 is located on the water outlet side of the one-way valve 20, the top rod 321 is slidably mounted in the temperature sensing shell 322, and the adjusting valve core 31 is mounted at the outer end of the top rod 321; the temperature sensing medium 323 is arranged in the temperature sensing shell 322, and the temperature sensing medium 323 is used for expanding when the temperature of the water in the water channel rises to a preset temperature so as to extend the ejector rod 321, so as to drive the regulating valve core 31 to move towards the direction close to the one-way valve 20; the temperature sensing medium 323 also serves to contract when cooled.

Specifically, the temperature sensing medium 323 expands when the temperature of the water in the valve housing 22 rises to a predetermined temperature, so that the push rod 321 can be driven to slide to extend the push rod 321; when the temperature of the water at the temperature sensing reaction part drops below a preset temperature, the temperature sensing medium 323 contracts, so that the push rod 321 can reset along with the temperature sensing medium 323 or driven by other resetting pieces.

The temperature control driving component 32 is a thermal bulb component, that is, the temperature sensing shell 322 and the temperature sensing medium 323 in the temperature sensing shell 322 form a thermal bulb, and together with the push rod 321, etc., form a thermal bulb component.

Alternatively, the temperature sensing medium 323 may be paraffin, methanol, toluene, or the like. It should be noted that the preset temperature is related to the selection of the temperature sensing medium 323, for example, when the temperature sensing medium 323 is paraffin, the preset temperature can be 37 degrees, and the like.

Further, as shown in fig. 3 to 9, the temperature controlled driving assembly 32 further includes a third elastic member 324, and the third elastic member 324 is used for making the regulating valve core 31 have a tendency of returning to the initial position. In this way, when the temperature sensing medium 323 contracts, the third elastic member 324 drives the adjustment valve body 31 to be restored together with the push rod 321, thereby improving the reliability and other performances of the return valve 100.

In an embodiment, the third elastic member 324 may be a spring, a spring plate, or a rubber band.

In this embodiment, as shown in fig. 3-9, the third elastic member 324 is a third spring. Thus, the structure can be simplified conveniently, and the performance of the spring is more stable, thereby improving the reliability.

Further, as shown in fig. 3 to 9, the third spring is sleeved outside the regulating valve core 31, and two ends of the third spring are respectively disposed on the inner support 361 and the regulating valve core 31, so that the regulating valve core 31 has a tendency of returning. In this way, not only the stability of the movement of the regulator valve body 31 can be improved, but also the space occupied in the direction of movement of the regulator valve body 31 can be reduced.

Further, as shown in fig. 3 to 9, the regulating valve core 31 includes a valve core main body 311 and a limit protrusion 313 protruding from a circumferential surface of the valve core main body 311, and two ends of the third spring are respectively disposed on the inner support 361 and the limit protrusion 313, so that the regulating valve core 31 has a tendency of returning.

Specifically, two ends of the third spring respectively abut against the limit convex part 313 and the inner support 361, so that the third spring is in a compressed state, and the limit valve core has a tendency of resetting.

Further, as shown in fig. 3 to 9, an end surface of one end (i.e., the end facing the second flow channel 12) of the valve core main body 311 is opened with an installation groove 314, and an outer end of the push rod 321 is installed in the installation groove 314.

Further, as shown in fig. 3 to 9, the valve body 311 is provided with a water passage hole 315 communicating with the mounting groove 314.

Specifically, the plurality of water through holes 315 are distributed at intervals in the circumferential direction of the valve body 311.

Specifically, the water passage hole 315 extends to an end surface of the valve body 311 facing one end of the second flow passage 12.

In this manner, the third flow channel 13 can be prevented from being blocked.

Further, as shown in fig. 3 to 9, the regulating valve core 31 further includes a sliding portion 312 provided at one end of the valve core body 311 (i.e., an end facing the check valve 20), and the sliding portion 312 is slidably installed in the installation through hole 3611.

The sliding portion 312 and the valve body 311 form a step structure to limit the movement of the adjustment valve core 31.

Specifically, the tip end of the sliding portion 312 (i.e., the end facing the check valve 20) is used for (the valve cover of) the valve housing 22 to abut against.

Of course, in other embodiments, the temperature sensing driving assembly may be configured in other structural forms, for example, the temperature sensing driving assembly further includes a temperature sensing seat, and a temperature sensing elastic sheet and an elastic resetting member that are disposed on the temperature sensing seat, so that the temperature sensing elastic sheet deforms when the temperature rises to extend the adjustment valve core 31, and the elastic resetting member retracts the adjustment valve core 31; and so on.

Of course, in other embodiments, a convex structure may be provided on the inner wall surface of the third flow passage 13 to mount the first spring, the regulator valve body 31, the third spring, and the like.

Further, as shown in fig. 3 to 9, the water return valve 100 further includes a fourth elastic member 40, the temperature-controlled driving component 32 is movably disposed in the waterway channel, and the fourth elastic member 40 is configured to make the temperature-controlled driving component 32 have a tendency to move toward the direction of approaching the check valve 20. Specifically, the temperature sensing case 322 is movably disposed in the water passage, and the fourth elastic member 40 is used to make the temperature sensing case 322 tend to move toward the one-way valve 20.

The slidable direction of the regulating valve core 31 and the movable direction of the temperature sensing shell 322 should be both directions approaching or departing from the check valve 20.

It is understood that the temperature-controlled driving assembly 32 formed by using the temperature-sensitive medium 323 such as paraffin generally has a temperature-sensing delay characteristic, i.e., after the temperature-controlled driving assembly 32 drives the check valve 20 to move to the initial position of the check valve 20 through the regulating valve core 31, the temperature-controlled driving assembly still has a tendency to drive the regulating valve core 31 to move, which may damage the regulating valve core 31.

However, in the present invention, the temperature control driving unit 32 is movably disposed in the water passage, and the fourth elastic member 40 is disposed to make the temperature control driving unit 32 tend to move toward the check valve 20, so that the adverse effect of the temperature sensing delay characteristic of the temperature sensing medium 323 such as paraffin can be eliminated.

Alternatively, as shown in fig. 3-9, the fourth elastic member 40 is a fourth spring. Specifically, the fourth spring is sleeved outside the temperature sensing shell 322, and one end of the fourth spring is connected to the inner wall surface of the water channel, and the other end of the fourth spring is connected to the temperature sensing shell 322, so that the temperature sensing shell 322 has a tendency of moving toward the direction close to the check valve 20.

Optionally, the spring constant of the third spring is less than the spring constant of the fourth spring.

Further, as shown in fig. 3 to 9, in order to improve the mounting and moving stability of the temperature control driving assembly 32, the temperature control assembly 30 further includes a supporting frame 35, the supporting frame 35 is fixedly mounted in the third flow channel 13, and the temperature control driving assembly 32 is mounted on the supporting frame 35.

Specifically, the supporting frame 35 is provided with a supporting hole, and the temperature sensing shell 322 is slidably mounted in the supporting hole, so that the temperature control driving component 32 is movably mounted in the water channel. Wherein, the support frame 35 is located on one side of the valve core sleeve 36 far away from the one-way valve 20.

Further, as shown in fig. 3 to 8, the first flow channel 11 includes a first flow section 111, one end of the first flow section 111 is provided with a first flow channel 11 port, the other end of the first flow section 111 is communicated with the third flow channel 13, and the extending direction of the first flow section 111 is the same as the extending direction of the third flow channel 13.

Optionally, a filter screen 70 is further disposed at the first flow passage 11.

Further, as shown in fig. 3 to 8, the second flow channel 12 includes a second flow segment 121, one end of the second flow segment 121 is provided with a second flow channel 12 port, the other end of the second flow segment 121 is communicated with a third flow channel 13, and the extending direction of the second flow segment 121 is the same as the extending direction of the third flow channel 13.

The temperature control assembly 30 is installed in the second flow section 121 and the third flow channel 13.

Optionally, as shown in fig. 3 to 8, the first flow segment 111, the third flow channel 13, and the second flow segment 121 are straight flow channels, and the first flow segment 111 and the second flow segment 121 are respectively disposed at two ends of the third flow channel 13.

Further, as shown in fig. 3 to 8, the first flow passage 11 further includes a third flow section 112 communicated with the first flow section 111, a communication position between the first flow section 111 and the third flow section 112 is communicated with the third flow passage 13, and one end of the third flow section 112 is provided with a port 13 of the third flow passage.

The second flow channel 12 further includes a fourth flow section 122 communicated with the second flow section 121, a communication position between the second flow section 121 and the fourth flow section 122 is communicated with the third flow channel 13, and a fourth flow channel opening is arranged at one end of the fourth flow section 122.

Of course, in other embodiments, the waterway flow passage may be designed in other structural forms, for example, the first flow passage 11, the second flow passage 12 and the third flow passage 13 may form an H-shaped structure.

Further, as shown in fig. 3 to 8, the valve core sleeve 36 is disposed in the middle section of the third flow passage 13.

Further, as shown in fig. 3 and 7, the valve body 10 includes a first valve body 10a and a second valve body 10b which are connected in a fitting manner, the first valve body 10a has a first flow passage 11 and a part of a third flow passage 13, and the second valve body 10b has a second flow passage 12 and a part of the third flow passage 13.

Further, as shown in fig. 3 and 7, the first valve body 10a is detachably connected to the second valve body 10 b.

Specifically, the first valve body 10a is clamped with the second valve body 10 b.

Optionally, a snap spring 60 is arranged at the clamping position of the first valve body 10a and the second valve body 10 b.

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 (18)

1. A water return valve, comprising:

the valve body is provided with a waterway runner, and the waterway runner comprises a first runner, a second runner and a third runner, wherein the first runner and the second runner are arranged at intervals, and the third runner is communicated with the first runner and the second runner;

the check valve is used for guiding the water in the first flow channel into the second flow channel in a one-way mode; the one-way valve is movably arranged in the waterway flow passage and blocks the third flow passage when in an initial position; and

the first elastic piece is arranged in the waterway flow passage and used for enabling the one-way valve to have the tendency of resetting to the initial position;

the check valve is used for leaving the initial position when the water pressure difference between the first flow passage and the second flow passage is increased to a preset pressure difference so as to open the third flow passage.

2. The water return valve according to claim 1 wherein said check valve is movably mounted in said third flow passage, said first elastic member being provided in said third flow passage;

the water return valve also comprises a temperature control component, the temperature control component comprises a temperature control driving component and an adjusting valve core, the adjusting valve core is positioned on the water outlet side of the one-way valve, and the adjusting valve core is movably arranged in the waterway flow channel in the direction far away from or close to the one-way valve;

the check valve is used for moving towards the direction close to the regulating valve core when the water pressure difference between the first flow passage and the second flow passage is increased to a preset pressure difference so as to open the third flow passage;

the temperature control driving assembly is arranged in the waterway runner and used for driving the regulating valve core to move towards the direction close to the one-way valve when the water temperature in the waterway runner rises to a preset temperature so as to drive the one-way valve away from the initial position to reset.

3. The water return valve according to claim 2, wherein the check valve has an initial distance from the regulating spool when the check valve is in the initial position, the initial distance being smaller than the sum of the maximum movable distance of the regulating spool and the maximum movable distance of the check valve and greater than or equal to the maximum movable distance of the regulating spool.

4. The water return valve according to claim 3, wherein the temperature control assembly further comprises a valve core sleeve, the valve core is sleeved in the third flow passage, and the regulating valve core is movably arranged in the valve core sleeve;

the first elastic piece is a first spring, the first spring is sleeved outside the one-way valve, and two ends of the first spring are respectively arranged on the one-way valve and the valve core sleeve, so that the one-way valve has a tendency of resetting to the initial position.

5. The water return valve according to claim 4, wherein the valve core sleeve is provided with a first water passing structure, and/or the adjusting valve core is provided with a second water passing structure, and/or a water passing gap is formed between the outer peripheral surface of the adjusting valve core and the inner wall surface of the valve core sleeve.

6. The water return valve according to claim 4, wherein an inner support is provided on an inner wall surface of the spool housing, the inner support has a mounting through-hole, one end of the adjustment spool is slidably mounted in the mounting through-hole, and the first end of the first spring is provided on the inner support.

7. The water return valve according to claim 6 wherein the temperature-controlled driving assembly comprises a push rod, a temperature-sensing shell and a temperature-sensing medium which expands when heated, the temperature-sensing shell is located on the water outlet side of the one-way valve, the push rod is slidably mounted in the temperature-sensing shell, and the adjusting valve core is mounted at the outer end of the push rod; the temperature sensing medium is arranged in the temperature sensing shell and is used for expanding when the temperature of water in the waterway flow passage rises to a preset temperature so as to enable the ejector rod to extend out, so that the regulating valve core is driven to move towards the direction close to the one-way valve; the temperature sensitive medium is also adapted to contract when cooled.

8. The water return valve according to claim 7, wherein said temperature control member further comprises a third elastic member for providing said adjustment spool with a tendency to return.

9. The water return valve according to claim 8, wherein the third elastic member is a third spring, the third spring is sleeved outside the adjusting valve core, and two ends of the third spring are respectively disposed on the inner support and the adjusting valve core, so that the adjusting valve core has a tendency of returning.

10. The water return valve according to claim 9, wherein the adjusting spool includes a spool body and a limit protrusion protruding from a circumferential surface of the spool body, an installation groove is formed in an end surface of one end of the spool body, and an outer end of the push rod is installed in the installation groove; two ends of the third spring are respectively arranged on the inner support and the limiting convex part, so that the adjusting valve core has a resetting trend; and the valve core main body is provided with a water through hole communicated with the mounting groove.

11. The return valve of claim 4, wherein said check valve includes a second elastic member, a valve housing, and a check valve element movably mounted in said valve housing, both ends of said second elastic member being disposed in said valve housing and said check valve element, respectively, so that said check valve element has a tendency to return to a closed position for closing said check valve; the first spring sleeve is arranged outside the valve shell, and two ends of the first spring are respectively arranged on the valve shell and the valve core sleeve, so that the one-way valve has the tendency of resetting to the initial position.

12. The water return valve according to claim 11 wherein said valve housing has a gear protrusion protruding from an outer peripheral surface thereof, and said first spring has a second end provided on said gear protrusion.

13. The return valve according to claim 12, wherein a seal ring protrusion is formed on an inner wall surface of the third flow passage, and the shift protrusion abuts against the seal ring protrusion when the check valve is in the initial position.

14. The water return valve according to claim 13, wherein said check valve further comprises a sealing ring installed on a side of said shift protrusion away from said regulating valve core, and when said check valve is in said initial position, said sealing ring is sandwiched between said sealing ring protrusion and said shift protrusion to block a third flow passage.

15. The water return valve according to claim 13 wherein said gear protrusions are spaced circumferentially of said valve housing to open said third flow path when said check valve is moved away from said initial position; or the gear convex part is an annular convex part, and a water through hole is formed in the gear convex part so as to open the third flow channel when the one-way valve leaves the initial position; and/or the presence of a gas in the gas,

and a water passing gap is formed between the end face of the gear convex part and the inner wall surface of the third flow passage so as to open the third flow passage when the one-way valve leaves the initial position.

16. A water supply system, comprising:

a gas heating device;

the water outlet end is connected with the gas water heater through a cold water pipe, a hot water pipe and a water mixing device; and

a water return valve according to any one of claims 1 to 15 having a first flow path connected to the hot water pipe and a second flow path connected to the cold water pipe.

17. The water supply system of claim 16, wherein the gas heating device is a gas water heater or a gas wall-hanging stove.

18. A water supply system, comprising:

a gas heating device;

the water outlet end is connected with the gas water heater through a cold water pipe, a hot water pipe and a water mixing device;

the water return valve according to any one of claims 1 to 15, wherein a second flow passage of the water return valve is connected to a cold water pipe or a water inlet pipe of the gas heating device; and

and one end of the water return pipe is connected to the hot water pipe, and the other end of the water return pipe is connected to the first flow channel of the water return valve.

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