Device for maintaining constant outlet water temperature of water heater and control logic thereof

Abstract

The invention discloses a device for keeping the water outlet temperature of a water heater constant and a control logic thereof, and the device comprises a main water path, a water tank water inlet flow path, a cold water inlet flow path, other bypass water paths, a water tank, a water mixing valve, a buffer tank, a hot water outlet, a cold water outlet, a water mixing valve, a buffer tank and a water using end, and the opening degrees of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are automatically controlled when other bypass water paths are switched on and off. The water pressures at multiple positions are collected, and the opening degrees of the water pressure regulators at the multiple positions are controlled according to the water pressure conditions, so that the water outlet temperature of the water heater is kept constant when other bypass water paths are opened and closed.

Description

Technical Field

[0001] The invention relates to a device for maintaining constant outlet water temperature of a water heater and control logic thereof. Background Art

[0002] A key problem with household water heaters during people's use is that when the bypass faucet is turned on and off, the water pressure in the water system will change dramatically. The change in water pressure will cause the water outlet temperature of the water heater to fluctuate, greatly affecting the comfort of water use. In addition, overheated hot water poses a risk of scalding, and overcold hot water can freeze the body during bathing. Currently, there is no better solution to this problem. Summary of the invention

[0003] In view of the above problems, the present invention provides a device for maintaining a constant outlet water temperature of a water heater and its control logic, which effectively solves the problems pointed out in the background technology.

[0004] The technical solution adopted by the present invention is:

[0005] A device for maintaining a constant outlet temperature of water from a water heater, comprising a main water path, a water tank inlet flow path connected to the main water path, a cold water inlet flow path and other bypass water paths, a water tank, a mixing valve and a buffer tank, wherein the water tank inlet flow path is connected to the interior of the water tank, the cold water inlet flow path is not connected to the interior of the water tank, the water tank is provided with a hot water outlet connected to the interior of the water tank, and a cold water outlet connected to the cold water inlet flow path, the hot water outlet and the cold water outlet are connected to the mixing valve, the outlet of the mixing valve is connected to the buffer tank, and the outlet of the buffer tank is connected to a water-using end;

[0006] A first water pressure regulator and a first water pressure sensor are provided at the intersection of the water tank water inlet flow path and the main water path;

[0007] A second water pressure regulator and a second water pressure sensor are provided at the hot water outlet; a third water pressure regulator and a third water pressure sensor are provided at the intersection of the cold water inlet flow path and the main water path;

[0008] The cold water outlet is provided with a fourth water pressure regulator and a fourth water pressure sensor.

[0009] Preferably, the water pressures detected by the first water pressure sensor, the second water pressure sensor, the third water pressure sensor and the fourth water pressure sensor are P1, P2, P3 and P4 respectively; the initial openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator when the device is turned on are p1, p2, p3 and p4 respectively; the current openings are p1′, p2′, p3′ and p4′ respectively; after each adjustment of the openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator, p1′, p2′, p3′ and p4′ are assigned to p1, p2, p3 and p4 respectively; until the device is turned off or the water use end stops using water for 30 seconds, p1, p2, p3 and p4 are restored to the initial openings.

[0010] Preferably, when the device starts to use water at the water end, it first adjusts the openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to the initial openings, maintains the openings for 1 minute, and then enters the automatic adjustment logic.

[0011] Preferably, the automatic adjustment logic is:

[0012] 1) When P1 changes, the change of P1 ΔP1 is calculated after T1. When P1 decreases, ΔP1 is a negative value, and when P1 increases, ΔP1 is a positive value. Then, the first water pressure regulator and the second water pressure regulator are adjusted as follows:

[0013] p1′=p1+k1*(-ΔP1);

[0014] p2′=p2+k2*(-ΔP1);

[0015] Among them, k1 and k2 are both adjustment coefficients. After adjustment, p1′ and p2′ are assigned to p1 and p2 respectively, and then the second water pressure regulator is adjusted twice:

[0016] After T1, the change of P2, ΔP2, is calculated. When P2 decreases, ΔP2 is a negative value, and when P2 increases, ΔP2 is a positive value.

[0017] p2′=p2+k2′*(-ΔP2);

[0018] Among them, k2′ is the adjustment coefficient, and p2′ is assigned to p2 after adjustment;

[0019] Repeat this step;

[0020] 2) When P3 changes, the change of P3 ΔP3 is calculated after T3. When P3 decreases, ΔP3 is a negative value, and when P3 increases, ΔP3 is a positive value. Then, the third water pressure regulator and the fourth water pressure regulator are adjusted as follows:

[0021] p3′=p3+k3*(-ΔP3);

[0022] p4′=p4+k4*(-ΔP3);

[0023] Among them, k3 and k4 are both adjustment coefficients. After adjustment, p3′ and p4′ are assigned to p3 and p4 respectively, and then the fourth water pressure regulator is adjusted twice:

[0024] After T3, the change of P4 ΔP4 is calculated. When P4 decreases, ΔP4 is a negative value, and when P4 increases, ΔP4 is a positive value.

[0025] p4′=p4+k4′*(-ΔP4);

[0026] Among them, k4′ is the adjustment coefficient, and p4′ is assigned to p4 after adjustment;

[0027] Repeat this step;

[0028] 3) When P1 and P3 do not change, the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are kept at the current openings unchanged.

[0029] Preferably, after the device enters the automatic adjustment logic, when the water end is using water and the opening changes, the device exits the automatic adjustment logic, and controls the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the current opening for 1 minute, and then enters the automatic adjustment logic again.

[0030] At the same time, the present invention also provides a control logic of a device for maintaining a constant outlet water temperature of a water heater. After the device is turned on, the water pressure values ​​of the first water pressure sensor, the second water pressure sensor, the third water pressure sensor and the fourth water pressure sensor are automatically obtained as P1, P2, P3 and P4 respectively, and the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are controlled to open to the initial openings p1, p2, p3 and p4 respectively, and then the control is performed according to the following steps:

[0031] 1) When using water at the water end, control the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the initial opening for 1 minute, and then enter the automatic adjustment logic;

[0032] 2) Automatic adjustment logic:

[0033] 21) When P1 changes, the change of P1 ΔP1 is calculated after T1. When P1 decreases, ΔP1 is a negative value, and when P1 increases, ΔP1 is a positive value. Then, the first water pressure regulator and the second water pressure regulator are adjusted as follows:

[0034] p1′=p1+k1*(-ΔP1);

[0035] p2′=p2+k2*(-ΔP1);

[0036] Among them, k1 and k2 are both adjustment coefficients. After adjustment, p1′ and p2′ are assigned to p1 and p2 respectively, and then the second water pressure regulator is adjusted twice:

[0037] After T1, the change of P2, ΔP2, is calculated. When P2 decreases, ΔP2 is a negative value, and when P2 increases, ΔP2 is a positive value.

[0038] p2′=p2+k2′*(-ΔP2);

[0039] Among them, k2′ is the adjustment coefficient, and p2′ is assigned to p2 after adjustment;

[0040] Repeat this step;

[0041] 22) When P3 changes, the change amount of P3 ΔP3 is calculated after T3. When P3 decreases, ΔP3 is a negative value, and when P3 increases, ΔP3 is a positive value. Then, the third water pressure regulator and the fourth water pressure regulator are adjusted as follows:

[0042] p3′=p3+k3*(-ΔP3);

[0043] p4′=p4+k4*(-ΔP3);

[0044] Among them, k3 and k4 are both adjustment coefficients. After adjustment, p3′ and p4′ are assigned to p3 and p4 respectively, and then the fourth water pressure regulator is adjusted twice:

[0045] After T3, the change of P4 ΔP4 is calculated. When P4 decreases, ΔP4 is a negative value, and when P4 increases, ΔP4 is a positive value.

[0046] p4′=p4+k4′*(-ΔP4);

[0047] Among them, k4′ is the adjustment coefficient, and p4′ is assigned to p4 after adjustment;

[0048] Repeat this step;

[0049] 23) When P1 and P3 do not change, keep the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator at the current opening unchanged;

[0050] 3) After the device enters the automatic adjustment logic, when the water end is using water and the opening changes, the device exits the automatic adjustment logic, and controls the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the current opening for 1 minute, and then enters the automatic adjustment logic again;

[0051] 4) When the device is shut down or the water end stops using water for 30 seconds, restore P1, P2, P3, and P4 to their initial openings.

[0052] Preferably, the T1 is determined according to the length of the water tank inlet flow path. The longer the water tank inlet flow path, the larger T1 is. The T2 is determined according to the length of the cold water inlet flow path. The longer the cold water inlet flow path, the larger T2 is.

[0053] Preferably, the k2′ and k4′ are determined by the water channel distance from the buffer tank to the water-using end. The longer the water channel distance is, the larger the k2′ and k4′ are.

[0054] The present invention collects water pressures at multiple locations and controls the openings of water pressure regulators at multiple locations according to the water pressure conditions, thereby maintaining a constant outlet water temperature of the water heater when other bypass water channels are switched on or off.

[0055] In the present invention, p1 and p3 are adjusted according to ΔP1 and ΔP3 respectively, and the first water pressure regulator P1 and the third water pressure regulator P3 have a certain hysteresis in response to the water pressure change. While the opening of the first water pressure regulator P1 and the third water pressure regulator P3 is adjusted, the second water pressure regulator P2 and the fourth water pressure regulator P4 are advanced-adjusted according to ΔP1 and ΔP3 to compensate for this lag time, and then a second adjustment is performed according to ΔP2 and ΔP4, thereby avoiding overshoot in the first adjustment of the second water pressure regulator P2 and the fourth water pressure regulator P4. This adjustment method is more accurate and can ensure the constant water outlet temperature of the water heater.

[0056] The present invention can delay the response time of the outlet water temperature to the change of the water pressure by arranging a buffer tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0058] Figure 2 Schematic diagram of the control logic of the present invention. DETAILED DESCRIPTION

[0059] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0060] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0061] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0065] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0066] Example 1

[0067] like Figure 1 As shown, a device for maintaining a constant outlet water temperature of a water heater comprises a main water path 1, a water tank inlet flow path 2, a cold water inlet flow path 3 and other bypass water paths 4 connected to the main water path 1, a water tank 5, a mixing valve 6 and a buffer tank 7, wherein the water tank inlet flow path 2 is connected to the interior of the water tank 5, the cold water inlet flow path 3 is not connected to the interior of the water tank 5, the water tank 5 is provided with a hot water outlet 8 connected to the interior of the water tank 5, and a cold water outlet 9 connected to the cold water inlet flow path 3, the hot water outlet 8 and the cold water outlet 9 are connected to the mixing valve 6, the outlet of the mixing valve 6 is connected to the buffer tank 7, and the outlet of the buffer tank 7 is connected to a water use end 11;

[0068] A first water pressure regulator and a first water pressure sensor are provided at the intersection of the water tank water inlet flow path 2 and the main water path 1;

[0069] The hot water outlet 8 is provided with a second water pressure regulator and a second water pressure sensor; the intersection of the cold water inlet flow path 3 and the main water path 1 is provided with a third water pressure regulator and a third water pressure sensor;

[0070] The cold water outlet 9 is provided with a fourth water pressure regulator and a fourth water pressure sensor.

[0071] Furthermore, the water pressures detected by the first water pressure sensor, the second water pressure sensor, the third water pressure sensor and the fourth water pressure sensor are P1, P2, P3 and P4 respectively, and the initial openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator when the device is turned on are p1, p2, p3 and p4 respectively, and the current openings are p1′, p2′, p3′ and p4′ respectively. After each adjustment of the openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator, p1′, p2′, p3′ and p4′ are assigned to p1, p2, p3 and p4 respectively, until the device is turned off or the water use end stops using water for 30 seconds, and then p1, p2, p3 and p4 are restored to the initial openings.

[0072] Furthermore, when the device starts to use water at the water end, it first adjusts the openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to the initial openings, maintains the openings for 1 minute, and then enters the automatic adjustment logic.

[0073] Furthermore, the automatic adjustment logic is:

[0074] 1) When P1 changes, the change of P1 ΔP1 is calculated after T1. When P1 decreases, ΔP1 is a negative value, and when P1 increases, ΔP1 is a positive value. Then, the first water pressure regulator and the second water pressure regulator are adjusted as follows:

[0075] p1′=p1+k1*(-ΔP1);

[0076] p2′=p2+k2*(-ΔP1);

[0077] Among them, k1 and k2 are both adjustment coefficients. After adjustment, p1′ and p2′ are assigned to p1 and p2 respectively, and then the second water pressure regulator is adjusted twice:

[0078] After T1, the change of P2, ΔP2, is calculated. When P2 decreases, ΔP2 is a negative value, and when P2 increases, ΔP2 is a positive value.

[0079] p2′=p2+k2′*(-ΔP2);

[0080] Among them, k2′ is the adjustment coefficient, and p2′ is assigned to p2 after adjustment;

[0081] Repeat this step;

[0082] 2) When P3 changes, the change of P3 ΔP3 is calculated after T3. When P3 decreases, ΔP3 is a negative value, and when P3 increases, ΔP3 is a positive value. Then, the third water pressure regulator and the fourth water pressure regulator are adjusted as follows:

[0083] p3′=p3+k3*(-ΔP3);

[0084] p4′=p4+k4*(-ΔP3);

[0085] Among them, k3 and k4 are both adjustment coefficients. After adjustment, p3′ and p4′ are assigned to p3 and p4 respectively, and then the fourth water pressure regulator is adjusted twice:

[0086] After T3, the change of P4 ΔP4 is calculated. When P4 decreases, ΔP4 is a negative value, and when P4 increases, ΔP4 is a positive value.

[0087] p4′=p4+k4′*(-ΔP4);

[0088] Among them, k4′ is the adjustment coefficient, and p4′ is assigned to p4 after adjustment;

[0089] Repeat this step;

[0090] 3) When P1 and P3 do not change, the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are kept at the current openings unchanged.

[0091] Furthermore, after the device enters the automatic adjustment logic, when the water end is using water and the opening changes, the device exits the automatic adjustment logic, and controls the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the current opening for 1 minute, and then enters the automatic adjustment logic.

[0092] At the same time, the present invention also provides a control logic of a device for maintaining a constant water outlet temperature of a water heater, such as Figure 2 As shown, after the device is turned on, the water pressure values ​​of the first water pressure sensor, the second water pressure sensor, the third water pressure sensor and the fourth water pressure sensor are automatically obtained as P1, P2, P3, and P4, respectively, and the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are controlled to open to the initial openings p1, p2, p3, and p4, respectively, and then control is performed according to the following steps:

[0093] 1) When using water at the water end, control the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the initial opening for 1 minute to provide time for the user to manually adjust the water temperature, and then enter the automatic adjustment logic;

[0094] 2) Automatic adjustment logic:

[0095] 21) When P1 changes, the change of P1 ΔP1 is calculated after T1. When P1 becomes smaller, ΔP1 is a negative value, and when P1 becomes larger, ΔP1 is a positive value. Then the first water pressure regulator and the second water pressure regulator are adjusted as follows (because the first water pressure regulator has a certain lag in response to the water pressure change, while adjusting the first water pressure regulator, the second water pressure regulator needs to be adjusted in advance to compensate for this lag time):

[0096] p1′=p1+k1*(-ΔP1);

[0097] p2′=p2+k2*(-ΔP1);

[0098] Among them, k1 and k2 are both adjustment coefficients. After adjustment, p1′ and p2′ are assigned to p1 and p2 respectively, and then the second water pressure regulator is adjusted for the second time to prevent overshoot during the first adjustment of the second water pressure regulator:

[0099] After T1, the change of P2, ΔP2, is calculated. When P2 decreases, ΔP2 is a negative value, and when P2 increases, ΔP2 is a positive value.

[0100] p2′=p2+k2′*(-ΔP2);

[0101] Among them, k2′ is the adjustment coefficient, and p2′ is assigned to p2 after adjustment;

[0102] Repeat this step;

[0103] 22) When P3 changes, the change of P3 ΔP3 is calculated after T3. When P3 decreases, ΔP3 is a negative value, and when P3 increases, ΔP3 is a positive value. Then the third water pressure regulator and the fourth water pressure regulator are adjusted as follows (because the third water pressure regulator has a certain lag in response to the water pressure change, the fourth water pressure regulator needs to be adjusted in advance to compensate for this lag time while adjusting the third water pressure regulator):

[0104] p3′=p3+k3*(-ΔP3);

[0105] p4′=p4+k4*(-ΔP3);

[0106] Among them, k3 and k4 are both adjustment coefficients. After adjustment, p3′ and p4′ are assigned to p3 and p4 respectively, and then the fourth water pressure regulator is adjusted for the second time to prevent the fourth water pressure regulator from overshooting during the first adjustment:

[0107] After T3, the change of P4 ΔP4 is calculated. When P4 decreases, ΔP4 is a negative value, and when P4 increases, ΔP4 is a positive value.

[0108] p4′=p4+k4′*(-ΔP4);

[0109] Among them, k4′ is the adjustment coefficient, and p4′ is assigned to p4 after adjustment;

[0110] Repeat this step;

[0111] 23) When P1 and P3 do not change, keep the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator at the current opening unchanged;

[0112] 3) After the device enters the automatic adjustment logic, when the water end is using water and the opening changes, the device exits the automatic adjustment logic, and controls the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the current opening for 1 minute, and then enters the automatic adjustment logic again;

[0113] 4) When the device is shut down or the water end stops using water for 30 seconds, restore P1, P2, P3, and P4 to their initial openings.

[0114] Furthermore, the T1 is determined according to the length of the water tank inlet flow path. The longer the water tank inlet flow path is, the larger T1 is. The T2 is determined according to the length of the cold water inlet flow path. The longer the cold water inlet flow path is, the larger T2 is.

[0115] Furthermore, the k2′ and k4′ are determined by the water channel distance from the buffer tank to the water-using end. The longer the water channel distance is, the larger the k2′ and k4′ are.

[0116] Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A device for maintaining a constant water temperature at the outlet of a water heater, characterized in that: The invention comprises a main water path (1), a water tank water inlet path (2) connected to the main water path (1), a cold water inlet path (3) and other bypass water paths (4), a water tank (5), a mixing valve (6) and a buffer tank (7), wherein the water tank water inlet path (2) is connected to the interior of the water tank (5), and the cold water inlet path (3) is not connected to the interior of the water tank (5); the water tank (5) is provided with a hot water outlet (8) connected to the interior of the water tank (5), and a cold water outlet (9) connected to the cold water inlet path (3); the hot water outlet (8) and the cold water outlet (9) are connected to the mixing valve (6); the outlet of the mixing valve (6) is connected to the buffer tank (7), and the outlet of the buffer tank (7) is connected to a water use end (11); a first water pressure regulator and a first water pressure sensor are provided at the intersection of the water tank water inlet path (2) and the main water path (1); A second water pressure regulator and a second water pressure sensor are provided at the hot water outlet (8); a third water pressure regulator and a third water pressure sensor are provided at the intersection of the cold water inlet flow path (3) and the main water path (1); The cold water outlet (9) is provided with a fourth water pressure regulator and a fourth water pressure sensor.

2. A device for maintaining a constant outlet water temperature of a water heater according to claim 1, characterized in that: The water pressures detected by the first water pressure sensor, the second water pressure sensor, the third water pressure sensor and the fourth water pressure sensor are P1, P2, P3 and P4 respectively. The initial openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator when the device is turned on are p1, p2, p3 and p4 respectively, and the current openings are p1′, p2′, p3′ and p4′ respectively. After each adjustment of the openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator, p1′, p2′, p3′ and p4′ are assigned to p1, p2, p3 and p4 respectively, until the device is turned off or the water use end stops using water for 30 seconds, and then p1, p2, p3 and p4 are restored to the initial openings.

3. A device for maintaining a constant outlet water temperature of a water heater according to claim 2, characterized in that: When the device starts to use water at the water end, it first adjusts the openings of the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to the initial openings, maintains the openings for 1 minute, and then enters the automatic adjustment logic.

4. A device for maintaining a constant outlet water temperature of a water heater according to claim 3, characterized in that: The automatic adjustment logic is: 1) When P1 changes, the change of P1 ΔP1 is calculated after T1. When P1 decreases, ΔP1 is a negative value, and when P1 increases, ΔP1 is a positive value. Then, the first water pressure regulator and the second water pressure regulator are adjusted as follows: p1′=p1+k1*(-ΔP1); p2′=p2+k2*(-ΔP1); Among them, k1 and k2 are both adjustment coefficients. After adjustment, p1′ and p2′ are assigned to p1 and p2 respectively, and then the second water pressure regulator is adjusted twice: After T1, the change of P2, ΔP2, is calculated. When P2 decreases, ΔP2 is a negative value, and when P2 increases, ΔP2 is a positive value. p2′=p2+k2′*(-ΔP2); Among them, k2′ is the adjustment coefficient, and p2′ is assigned to p2 after adjustment; Repeat this step; 2) When P3 changes, the change of P3 ΔP3 is calculated after T3. When P3 decreases, ΔP3 is a negative value, and when P3 increases, ΔP3 is a positive value. Then, the third water pressure regulator and the fourth water pressure regulator are adjusted as follows: p3′=p3+k3*(-ΔP3); p4′=p4+k4*(-ΔP3); Among them, k3 and k4 are both adjustment coefficients. After adjustment, p3′ and p4′ are assigned to p3 and p4 respectively, and then the fourth water pressure regulator is adjusted twice: After T3, the change of P4 ΔP4 is calculated. When P4 decreases, ΔP4 is a negative value, and when P4 increases, ΔP4 is a positive value. p4′=p4+k4′*(-ΔP4); Among them, k4′ is the adjustment coefficient, and p4′ is assigned to p4 after adjustment; Repeat this step; 3) When P1 and P3 do not change, the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are kept at the current openings unchanged.

5. A device for maintaining a constant outlet water temperature of a water heater according to claim 4, characterized in that: After the device enters the automatic adjustment logic, when the water-using end is using water and the opening changes, the device exits the automatic adjustment logic, and controls the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the current opening for 1 minute, and then enters the automatic adjustment logic again.

6. A control logic of a device for maintaining a constant outlet water temperature of a water heater as claimed in any one of claims 1 to 5, characterized in that: After the device is turned on, the water pressure values ​​of the first water pressure sensor, the second water pressure sensor, the third water pressure sensor and the fourth water pressure sensor are automatically obtained as P1, P2, P3, and P4, respectively, and the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator are controlled to open to the initial openings p1, p2, p3, and p4, respectively, and then control is performed according to the following steps: 1) When using water at the water end, control the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the initial opening for 1 minute, and then enter the automatic adjustment logic; 2) Automatic adjustment logic: 21) When P1 changes, the change of P1 ΔP1 is calculated after T1. When P1 decreases, ΔP1 is a negative value, and when P1 increases, ΔP1 is a positive value. Then, the first water pressure regulator and the second water pressure regulator are adjusted as follows: p1′=p1+k1*(-ΔP1); p2′=p2+k2*(-ΔP1); Among them, k1 and k2 are both adjustment coefficients. After adjustment, p1′ and p2′ are assigned to p1 and p2 respectively, and then the second water pressure regulator is adjusted twice: After T1, the change of P2, ΔP2, is calculated. When P2 decreases, ΔP2 is a negative value, and when P2 increases, ΔP2 is a positive value. p2′=p2+k2′*(-ΔP2); Among them, k2′ is the adjustment coefficient, and p2′ is assigned to p2 after adjustment; Repeat this step; 22) When P3 changes, the change amount of P3 ΔP3 is calculated after T3. When P3 decreases, ΔP3 is a negative value, and when P3 increases, ΔP3 is a positive value. Then, the third water pressure regulator and the fourth water pressure regulator are adjusted as follows: p3′=p3+k3*(-ΔP3); p4′=p4+k4*(-ΔP3); Among them, k3 and k4 are both adjustment coefficients. After adjustment, p3′ and p4′ are assigned to p3 and p4 respectively, and then the fourth water pressure regulator is adjusted twice: After T3, the change of P4 ΔP4 is calculated. When P4 decreases, ΔP4 is a negative value, and when P4 increases, ΔP4 is a positive value. p4′=p4+k4′*(-ΔP4); Among them, k4′ is the adjustment coefficient, and p4′ is assigned to p4 after adjustment; Repeat this step; 23) When P1 and P3 do not change, keep the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator at the current opening unchanged; 3) After the device enters the automatic adjustment logic, when the water end is using water and the opening changes, the device exits the automatic adjustment logic, and controls the first water pressure regulator, the second water pressure regulator, the third water pressure regulator and the fourth water pressure regulator to maintain the current opening for 1 minute, and then enters the automatic adjustment logic again; 4) When the device is shut down or the water end stops using water for 30 seconds, restore P1, P2, P3, and P4 to their initial openings.

7. The control logic of the device for maintaining a constant outlet water temperature of a water heater according to claim 6, characterized in that: The T1 is determined according to the length of the water tank inlet flow path. The longer the water tank inlet flow path is, the larger T1 is. The T2 is determined according to the length of the cold water inlet flow path. The longer the cold water inlet flow path is, the larger T2 is.

8. The control logic of the device for maintaining a constant outlet water temperature of a water heater according to claim 7, characterized in that: The k2' and k4' are determined by the water channel distance from the buffer tank to the water-using end. The longer the water channel distance is, the larger the k2' and k4' are.

Images