A constant temperature water heater

Abstract

The invention discloses a constant temperature water heater, comprising a heating tank, a valve body and a control system, wherein the valve body is provided with a cold water inlet pipe, a cold water outlet pipe, a hot water inlet pipe and a warm water outlet pipe, and the valve body is provided with a mixing chamber, which is connected with the cold water inlet pipe, the hot water inlet pipe and the warm water outlet pipe, and a temperature regulating valve is installed in the mixing chamber, wherein the characteristics are as follows: a warm water temperature detection device is installed on the warm water outlet pipe, the warm water temperature detection device is connected with the control system, a hot water temperature detection device is arranged in the heating tank, a flow detection device and a flow regulating valve are arranged on the valve body, the flow regulating valve is transmission-connected with a flow valve driving unit, and the hot water temperature detection device, the flow detection device and the flow valve driving unit are all connected with the control system. The constant temperature water heater can automatically limit the water outlet flow when the difference between the cold water temperature and the set outlet water temperature is large, and prolong the constant temperature water outlet time while ensuring the user experience.

Description

Technical Field

[0001] The invention relates to a continuous flow heating water heater, in particular to a constant temperature water heater. Background Art

[0002] At present, the warm water for household use is mainly obtained by heating the municipal water supply with an electric water heater to obtain high-temperature water, and then mixing it with the low-temperature municipal water supply to obtain suitable warm water. The mixing is generally carried out through a mixing valve, and the temperature of the warm water can be adjusted by changing the mixing ratio of high-temperature water and municipal water supply. In the past, the mixing valve was mostly adjusted by mechanical direct adjustment, but now it is mostly adjusted by electronic control.

[0003] For example, a Chinese patent (patent number 201110396052.1) provides a thermostatic faucet for an electric water heater, which is connected between an ordinary thermal storage water heater and a water-using device such as a shower, and is used to achieve constant temperature water discharge. When the thermostatic faucet for an electric water heater is in use, one branch of the cold water entering the faucet body enters the water heater and pushes out the hot water in the water heater; the other branch directly enters the thermostatic valve core and mixes with the pushed out hot water. When the temperature difference between the cold water temperature and the set outlet water temperature is large in winter, the water temperature in the thermal storage water heater will drop rapidly during the water use process. When the outlet water temperature in the thermal storage water heater drops, in order to ensure that the outlet water temperature of the thermostatic faucet is constant, the piston in the thermostatic valve core will move toward the cold water inlet, thereby reducing the flow area of ​​the cold water inlet and reducing the proportion of cold water; while the piston moves toward the cold water inlet, the flow area of ​​the hot water inlet will increase, and the proportion of hot water will increase. The hot water flowing out of the water heater is replaced by the cold water entering the water heater. The proportion of hot water in the thermostatic valve core increases, and the amount of cold water entering the water heater will also increase accordingly, which will further accelerate the drop in the water temperature in the water heater. At this time, the piston in the thermostatic valve core needs to move further toward the cold water inlet to further reduce the proportion of cold water and increase the proportion of hot water. The piston sliding in the thermostatic valve core has a limit value. When the piston moves to the limit position toward the cold water inlet, the flow area of ​​the cold water inlet and the hot water inlet no longer changes. At this time, the thermostatic valve core cannot automatically change the mixing ratio of cold and hot water to keep the outlet water temperature at the set value. At this time, the outlet water temperature of the thermostatic valve core will be lower than the set temperature and continue to drop. In actual use, when taking a bath in winter, after a certain period of bathing, the outlet water temperature will suddenly drop continuously. However, the human body has a low tolerance for cold, and low-temperature water will have a strong adverse stimulation on the user's body, which will seriously affect the user's experience. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a constant temperature water heater that can automatically limit the water flow rate when the difference between the cold water temperature and the set water outlet temperature is large, thereby extending the constant temperature water outlet time while ensuring user experience.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: a constant temperature water heater, including a heating tank, a valve body and a control system, the valve body is provided with a cold water inlet pipe, a cold water outlet pipe, a hot water inlet pipe, a warm water outlet pipe and a cold water branch pipe, the cold water inlet pipe and the cold water outlet pipe are connected, and the cold water outlet pipe and the hot water inlet pipe are respectively connected to the water inlet and the water outlet of the heating tank; a mixing water chamber is provided on the valve body, a temperature regulating valve is installed in the mixing water chamber, the mixing water chamber is connected to the hot water inlet pipe and the warm water outlet pipe, and the mixing water chamber is connected to the cold water inlet pipe through the cold water branch pipe, and the characteristic is that: a warm water temperature detection device is installed on the warm water outlet pipe, the warm water temperature detection device is connected to the control system, a hot water temperature detection device is arranged in the heating tank, a flow detection device and a flow regulating valve are arranged on the valve body, the flow regulating valve is transmission-connected with a flow valve driving unit, and the hot water temperature detection device, the flow detection device and the flow valve driving unit are all connected to the control system.

[0006] Through the above technical solution, the setting of the warm water temperature detection device can detect the water temperature of the warm water outlet pipe, and then the control system adjusts the temperature regulating valve according to the difference between the measured actual water outlet temperature and the set temperature, and changes the cold and hot water mixing ratio of the temperature regulating valve series, so that the actual water outlet temperature and the set temperature of the control system are kept constant. The hot water temperature detection device is set in the heating tank, and can detect the hot water temperature in the heating tank, so that the control system can record the temperature in the heating tank and obtain the water temperature change in the heating tank per unit time. The flow detection device can be set on the cold water inlet pipe, the cold water outlet pipe, the hot water inlet pipe or the warm water outlet pipe, so as to detect the overall inlet and outlet flow of the valve body or the inlet and outlet flow of the heating tank.

[0007] After the constant temperature water heater is installed, the heating tank heats the water stored therein so that its temperature reaches and remains at the set value of the control system. When water is used, cold water enters the heating tank through the water inlet of the heating tank, and the water temperature in the heating tank will change. If the temperature of the cold water flowing into the heating tank from the outside is high (or not much different from the warm water outlet temperature set by the user) and is within the heating capacity of the heating tank (the heating element in the heating tank works to keep the water temperature in the heating tank from dropping), the flow control valve does not limit the flow of water. If the water temperature in the heating tank drops significantly, the control system calculates the temperature difference between cold water and warm water according to the power of the heating element, the flow detection device, the hot water temperature detection device or the power of the heating element, the flow detection device, the hot water temperature detection device, and the warm water temperature detection device, and controls the flow regulating valve according to the flow control data of the control system to reduce the water flow, and reduce the water flow of the warm water outlet pipe without seriously affecting the user experience.

[0008] The flow detection device can be installed on the cold water inlet pipe, cold water outlet pipe, hot water inlet pipe or warm water outlet pipe, so as to detect the water flow in the valve body and know whether there is water flow in the valve body and the size of the water flow. The flow detection device can act as a switch, and the control system is turned on and off according to the presence or absence of water flow in the valve body detected by the flow detection device.

[0009] At the same time, when the control system is working, the flow detection device can collect the flow data in the valve body and transmit the flow data to the control system. When the flow detection device is set in the cold water inlet pipe or the warm water outlet pipe, the flow rate of the cold water inlet pipe or the warm water outlet pipe can be detected. Assume that during the normal use of warm water, the water temperature inside the heating tank continues to drop. At this time, the heating element in the heating tank continues to work, and the temperature of the warm water outlet pipe is stabilized at W under the action of the thermostatic valve core. At t1 during use, the temperature detected by the hot water temperature detection device is G1. At t2, the water temperature in the heating tank drops to G2. During the pooling process, the heating element is always in working state, the heating power is constant at P, and the volume of the heating tank is L. The total flow Q during this period can be obtained through the flow detection device. The specific heat capacity of water is C. The calculation formula:

[0010] (G2-G1)×C×L+P×(t2-t1)=Q×C×ΔT

[0011] ΔT can be obtained, which is the difference between the water temperature of the warm water outlet pipe and the water temperature of the cold water inlet pipe. After obtaining this value, the control system can adjust the flow control valve according to the value and the control data stored in the control system, so that the outlet water temperature remains constant, and the warm water output is gradually reduced without seriously affecting the user experience, until the flow through the heating tank is adapted to the heating capacity of the heating element, so that the water temperature in the heating tank no longer continues to decrease. This design can ensure the constant temperature of the warm water outlet on the one hand, avoid cold water irritating the user and causing the user to have a bad user experience; on the other hand, it can gradually reduce the water output during use to serve the purpose of reminding the user.

[0012] When the flow control system is set at the water inlet or outlet of the heating tank, ΔT can also be calculated by the formula.

[0013] Assume that at t1, the temperature inside the heating tank is G1 and the cold water temperature is T0;

[0014] At t2, the temperature inside the heating chamber is G2;

[0015] Then C×(G1+G2) / 2×Q=C×Q×T0+(G1-G2)×L×C+P×(t2-t1)

[0016] Then, according to the set value W, ΔT can be obtained according to W-T0.

[0017] In addition, compared with directly measuring the temperature of the cold water inlet pipe, this method can avoid the sudden change of the water flow rate caused by the sudden change of the water temperature of the cold water inlet pipe. After the cold water enters the heating tank, it will mix with the water in the heating tank, thereby eliminating the change of the water flow rate caused by the large temperature change of the cold water in a short time.

[0018] Preferably, the flow valve driving unit includes a flow regulating motor, a second driving gear installed on the output shaft of the flow regulating motor, and a second driven gear installed on the flow valve stem of the flow regulating valve, the second driving gear and the second driven gear are meshed, and the flow regulating motor is a stepping or servo motor.

[0019] Through the above technical solution, the control system can conveniently and reliably automatically control the flow regulating valve, so that the water flow of the water heater meets the requirements of the control system. The flow regulating valve is controlled by using a stepper motor or a servo motor in conjunction with the second driving gear and the second driven gear. The overall structure is relatively simple and compact, and has good control accuracy.

[0020] Preferably, it also includes a temperature control drive unit that is transmission-connected to the temperature control valve, the temperature control drive unit includes a temperature control motor, a first driving gear installed on the temperature control motor, and a first driven gear installed on the temperature control valve stem of the temperature control valve. The temperature control motor is connected to the control system, and the temperature control motor is a stepper or servo motor.

[0021] Through the above technical solution, the outlet water temperature can be easily controlled electronically, and the user can directly set the outlet water temperature on the control system. After the outlet water temperature is set, the control system can adjust the outlet water temperature of the temperature control valve to keep the outlet water temperature at the set temperature. The temperature control valve is controlled by using a stepper motor or a servo motor in conjunction with the first driving gear and the first driven gear. The overall structure is relatively simple and compact, and has good control accuracy.

[0022] Preferably, the temperature regulating valve is a thermostatic valve core.

[0023] Through the above technical solution, the temperature regulating valve is a thermostatic valve core. After the outlet water temperature is set on the control system, the thermostatic valve core only needs to be adjusted once to ensure the outlet water temperature of the thermostatic valve core. When the temperature or pressure of hot and cold water changes, the piston inside the thermostatic valve core will automatically adjust the water inlet ratio of hot and cold water so that the outlet water temperature always remains at the set value. If an ordinary mixing valve is used as a temperature regulating valve, when the temperature and pressure of hot and cold water change, the valve stem of the mixing valve needs to be repeatedly turned to adjust the mixing ratio of hot and cold water to keep the outlet water temperature constant. Using a thermostatic valve core can reduce the wear of the thermostatic motor during use and extend the service life of the thermostatic motor.

[0024] Preferably, the flow detection device includes a Hall element and a magnetic rotor, the Hall element is arranged outside the valve body, and the magnetic rotor is arranged in the flow channel of the cold water inlet pipe or the cold water outlet pipe or the hot water inlet pipe or the warm water outlet pipe.

[0025] The flow of water in the valve body can be detected relatively conveniently. When water flows in the flow channel of the valve body, the magnetic rotor rotates under the action of the water flow. When the magnetic rotor rotates, the Hall element on the outside of the valve body detects the speed of the magnetic rotor, thereby determining whether there is water flowing in the flow channel. The flow detection device is a common component in the water heating industry, especially in electric water heaters, and can be purchased directly on the market, so it will not be described here.

[0026] Preferably, the valve body includes a mixing water valve body and a cold water valve body, the mixing water chamber is arranged in the mixing water valve body, the cold water inlet pipe, the cold water outlet pipe and the cold water branch pipe are located on the cold water valve body, and the mixing water chamber is connected with the cold water inlet pipe and the cold water outlet pipe through the cold water branch pipe.

[0027] Through the above technical solution, the cold water inlet pipe, the cold water outlet pipe and the cold water branch pipe can form a three-way structure, so that the thermostatic valve has a water supply function. After the cold water enters the cold water valve body from the cold water inlet pipe, it flows to the mixing water valve body through the cold water branch pipe, and enters the heating tank through the cold water and warm water outlet pipes, thereby reducing the required tap water inlets and facilitating installation. At the same time, the split valve body can simplify the valve body structure, facilitate the arrangement of the inlet and outlet pipes, and facilitate the production and processing of the valve body.

[0028] Preferably, the valve body also includes a hot water valve body, and the hot water inlet pipe and the warm water outlet pipe are located on the hot water valve body. The hot water valve body is also provided with a hot water outlet pipe and a warm water inlet pipe. The hot water inlet pipe is connected to the mixing water chamber of the mixing water valve body through the hot water outlet pipe, and the warm water outlet pipe is connected to the mixing water chamber of the mixing water valve body through the warm water inlet pipe.

[0029] Through the above technical scheme, the setting of the hot water valve body can make the arrangement of the hot water inlet pipe and the warm water outlet pipe more flexible, so that the positions of the hot water inlet pipe and the cold water outlet pipe can be adapted to the positions of the cold water inlet pipe and the warm water outlet pipe of the heating tank, so as to facilitate the installation between the two.

[0030] Preferably, the cold water valve body and / or hot water valve body comprises a cavity with an opening at one end, a cold water branch pipe or a hot water outlet pipe is arranged in the cavity, one end of the cold water branch pipe or the hot water outlet pipe extends from the closed end of the cavity for connecting with the mixing valve body, and the other end is in the cavity, a plug is arranged at the open end of the cavity, and a filter is arranged between the plug and the end of the inner tube.

[0031] Through the above technical solution, the water entering the thermostatic valve core can be filtered to prevent solid particles mixed in the water from entering the thermostatic valve core and causing damage to the thermostatic valve core.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The control system can automatically adjust the mixing ratio of cold and hot water according to the set temperature to keep the outlet water temperature constant. The water temperature of the warm water outlet pipe can be detected by the warm water temperature detection device, and then the outlet water temperature of the temperature regulating valve can be corrected by comparing it with the outlet water temperature set by the user and the water temperature of the warm water outlet pipe, so that the actual outlet water temperature is always the same as the outlet water temperature set by the user. 2. The addition of a hot water temperature detection device, a flow detection device and a flow control valve core can realize the temperature difference calculation between the inlet water temperature and the outlet water temperature, so as to adjust the flow rate in real time according to the temperature difference between the two, gradually reduce the temperature drop rate in the heating tank, and extend the constant temperature water outlet time, so as to avoid the user from suddenly dropping the outlet water temperature during the bathing process, causing strong stimulation to the human body and affecting the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of an embodiment;

[0034] Figure 2 It is a schematic structural diagram of the whole valve body of the embodiment;

[0035] Figure 3 for Figure 2 The schematic diagram of the structure after removing the temperature control motor and the flow control motor;

[0036] Figure 4 It is a schematic diagram of the valve body structure;

[0037] Figure 5 This is the exploded view of the valve body;

[0038] Figure 6 is a cross-sectional schematic diagram of a valve body;

[0039] Figure 7 It is a schematic diagram of the structure of the water mixing valve body;

[0040] Figure 8 It is a structural schematic diagram of a hot water valve body;

[0041] Fig. 9 is a cross-sectional schematic diagram of a cold water valve body;

[0042] Fig.10 It is a partial cross-sectional view of the heating tank.

[0043] Figure numerals: 1, heating tank; 13, heating element; 14, hot water temperature detection device; 2, valve body; 21, hot water valve body; 211, cavity; 212, hot water outlet pipe; 213, warm water inlet pipe; 214, temperature measuring port; 22, cold water valve body; 221, cavity; 222, cold water branch pipe; 24, inlet pipe; 25, mixing water valve body; 251, cold water sleeve; 252, hot water sleeve; 253, warm water sleeve; 254, mixing water chamber; 255, hot water connecting port; 26, plug; 27, filter; 28, flange seat; 3, temperature control drive unit; 31, thermostatic motor; 32, first driven gear; 33, constant temperature valve core; 331. Temperature control valve stem; 34. First driving gear; 35. Temperature regulating valve; 4. Flow drive unit; 41. Flow regulating motor; 42. Second driven gear; 43. Flow regulating valve core; 431. Flow valve stem; 44. Second driving gear; 5. Flow detection device; 51. Hall element; 52. Magnetic rotor; 61. Cold water inlet pipe; 62. Warm water outlet pipe; 63. Cold water outlet pipe; 64. Hot water inlet pipe; 65. Water inlet; 66. Water outlet; 7. Warm water temperature detection device. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0045] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0046] like Figure 1 and Figure 2 As shown, a constant temperature water heater comprises a heating tank 1, a valve body 2 and a control system (not shown in the figure). The heating tank 1 is provided with a water inlet 65 and a water outlet 66. The heating tank 1 is provided with an electric heating element 13 and a hot water temperature detection device 14. The hot water temperature detection device 14 can use a thermocouple, and the thermocouple converts the water temperature in the heating tank 1 into an electrical signal and transmits it to the control system. The heating tank 1 is provided with a water inlet 65 and a water outlet 64. Cold water enters the heating tank 1 through the water inlet 65, and then flows out from the water outlet 66 after being heated by the electric heating element 13 in the heating tank 1. The hot water temperature sensor 14 is connected to the control system to detect the water temperature in the tank. When the water temperature in the heating tank 1 does not reach the preset temperature of the control system, the control system controls the electric heating element in the heating tank 1 to heat the water in the heating tank 1. When the water temperature in the heating tank 1 reaches the preset temperature of the control system, the control system controls the electric heating element 13 in the heating tank 1 to work intermittently to maintain the temperature in the heating tank 1 at the preset temperature of the system.

[0047] like Figures 2~4 As shown, the valve body 2 is provided with a cold water inlet pipe 61, a warm water outlet pipe 62, a cold water outlet pipe 63, and a hot water inlet pipe 64. The cold water outlet pipe 63 is connected to the water inlet 65 of the heating tank 1, and the hot water inlet pipe 64 is connected to the water outlet 66 of the heating tank 1. The valve body 2 includes a mixing valve body 25, a cold water valve body 22, and a hot water valve body 21. The cold water valve body 22 and the hot water valve body 21 are inserted on both sides of the mixing valve body 25. The thermostatic valve core 33 is installed on the mixing valve body 25. After the cold water enters the valve body 2, it is divided into two paths. One path enters the heating tank 1 from the cold water outlet pipe 63, and the other path enters the thermostatic valve core 33 through the mixing valve body 25. After the hot water flows out of the heating tank 1 , it enters the thermostatic valve core 33 through the hot water inlet pipe 64 of the valve body 2 , and the cold water and the hot water are mixed in the thermostatic valve core 33 , and then flow out from the warm water outlet pipe 62 of the valve body 2 .

[0048] A mixing chamber 254 is provided on the mixing valve body 25, and a thermostatic valve core 33 is installed in the mixing chamber 254. A temperature control valve stem 331 of the thermostatic valve core 33 is located outside the mixing chamber 254 and is connected to a thermostatic motor 31 through a first driven gear 32 and a first driving gear 34. The thermostatic motor 31 can use a stepping motor or a servo motor. The thermostatic motor 31 is connected to a control system, and the control system can control the rotation direction and rotation angle of the thermostatic motor 31, thereby driving the temperature control valve stem 331 to rotate and changing the set temperature of the thermostatic valve core 33.

[0049] like Figure 7 As shown, the water mixing valve body 25 includes a water mixing chamber 254 arranged vertically on the wall, and the opening of the water mixing chamber 254 faces the outside of the wall. A cold water sleeve 251 and a hot water sleeve 252 are arranged on the side of the water mixing chamber 254. The cold water sleeve 251 is connected to the inside of the water mixing chamber 254 through a hot water connecting port 255, and the hot water sleeve 252 is connected to the inside of the water mixing chamber 254 through a cold water connecting port. The cold water connecting port and the hot water connecting port 255 are arranged alternately. The thermostatic valve core 33 is installed in the water mixing chamber 254, and the hot water inlet of the thermostatic valve core 33 is connected to the hot water connecting port 255 and is separated from the cold water connecting port by a sealing ring; the cold water inlet of the thermostatic valve core 33 is connected to the cold water connecting port and is separated from the hot water connecting port 255 by a sealing ring. Thus, the hot water entering from the hot water sleeve 252 enters the hot water inlet of the thermostatic valve core 33, and the cold water entering from the cold water sleeve 251 enters the cold water inlet of the thermostatic valve core 33, and the cold water and the hot water will not mix outside the thermostatic valve core 33. After the cold water and the hot water enter the thermostatic valve core 33, they are mixed inside the thermostatic valve core 33, and then flow out from the bottom of the thermostatic valve core 33. The mixing valve body 25 is also provided with a warm water sleeve 253, which is located below the hot water sleeve 252 and is connected to the bottom of the mixing water chamber 254. After the mixed warm water flows out from the bottom of the thermostatic valve core 33, it enters the warm water sleeve 253 through the bottom of the mixing water chamber 254. The thermostatic valve core 33 is a common accessory in the industry and can be purchased directly. In actual use, the thermostatic valve core in the reference document may be used, or the structure of the thermostatic valve core disclosed in patent documents such as Patent No. 201380074664.6, 201710690445.0 or 201210218398.7 may be used. The thermostatic valve core 33 is a prior art and will not be described in detail here.

[0050] The cold water valve body 22 includes a cavity 221, which is cylindrical, with an opening at one end and a closed end at the other end. A cold water branch pipe 222 is arranged in the cavity 221, with one end of the cold water branch pipe 222 extending from the closed end of the cavity 221, and the other end of the cold water branch pipe 222 is located inside the cavity 221. One end of the cold water branch pipe 222 extending out of the cavity 221 is connected to the cold water sleeve 251. A plug 26 is arranged at the open end of the cavity 221, and a threaded seal is formed between the plug 26 and the cavity 221. A filter screen 27 is arranged between the plug 26 and one end of the cold water branch pipe 222 located in the cavity 221. The cold water inlet pipe of the cold water valve body 22 is connected to the inside of the cavity 221, and the cold water outlet pipe 63 is connected to the inside of the cold water branch pipe 222. When cold water enters the cold water valve body 22 from the cold water inlet pipe 61, it first enters the cavity 221 and is located outside the cold water branch pipe 222, then flows toward the open end of the cavity 221, and then enters the cold water branch pipe 222 through the filter 27. After the cold water enters the cold water branch pipe 222, one path leads to the mixing valve body 25, and the other path leads to the cold water outlet pipe 63. The cold water inlet pipe 61 is separately arranged from the cold water valve body 22, and the cold water inlet pipe 61 is connected to the cavity 221 of the cold water valve body 22 through the flange seat 28. A flow detection device 5 is installed on the cold water inlet pipe 61 to detect whether there is water flow in the cold water inlet pipe 61. The flow detection device 5 is connected to the control system. When the flow detection device 5 detects water flow, the control system controls the thermostat motor 31, the warm water temperature detection device 7 and the flow regulating motor 41 to work. The warm water temperature detection device 7 can use a temperature sensing probe made of a thermocouple, and when working, it converts the water temperature into an electrical signal and inputs it into the control system. The flow detection device 5 can use a Hall flow meter commonly used on water heaters, which can be directly purchased. The flow detection device 5 includes a Hall element 51 and a magnetic rotor 52. The magnetic rotor 52 is arranged in the cold water inlet pipe 61. When water flows through the cold water inlet pipe 62, the magnetic rotor 52 rotates. The Hall element 51 on the outside of the cold water inlet pipe 61 can sense the rotation of the magnetic rotor 52. The rotation speed of the magnetic rotor 52 changes linearly with the water flow velocity in the cold water inlet pipe 61, so that the water flow in the cold water inlet pipe 61 can be detected.

[0051] like Figure 6 and Figure 8As shown, the hot water valve body 21 includes a cavity 211, which is cylindrical, with an opening at one end and a closed end. A hot water outlet pipe 212 is arranged in the cavity 211, with one end of the hot water outlet pipe 212 extending from the closed end of the cavity 211, and the other end of the hot water outlet pipe 212 is inside the cavity 211. One end of the hot water outlet pipe 212 extending out of the cavity 211 is connected to the hot water sleeve 252. A plug 26 is arranged at the open end of the cavity 211, and a threaded seal is formed between the plug 26 and the cavity 211. A filter screen 27 is arranged between the plug 26 and one end of the hot water outlet pipe 212 in the cavity 211. The hot water inlet pipe 64 of the hot water valve body 21 is connected to the inside of the cavity 211. After hot water enters the hot water valve body 21 from the hot water inlet pipe 64, it first enters the cavity 211 and is outside the hot water outlet pipe 212, then flows toward the open end of the cavity 211, and then enters the hot water outlet pipe 212 through the filter 27. After entering the hot water outlet pipe 212, the hot water flows out from the end of the hot water outlet pipe 212 outside the cavity 211 and enters the water mixing valve body 25.

[0052] The hot water valve body 21 is also provided with a warm water inlet pipe 213, which is inserted into the warm water sleeve 253. The warm water inlet pipe 213 is provided with a temperature measuring port 214, and the temperature measuring port 214 is provided with a warm water temperature detection device 7 for detecting the water temperature inside the warm water inlet pipe 213. A warm water outlet pipe 62 is provided below the warm water inlet pipe 213, and the warm water outlet pipe 62 and the hot water valve body 21 are connected through a flange seat 28. A flow regulating valve core 43 is installed on the warm water outlet pipe 62, and a flow regulating motor 41 is provided on one side of the flow regulating valve core 43 to drive the flow valve stem 331 of the flow regulating valve core 43 to rotate. The flow regulating motor 41 can use a stepping motor or a servo motor. The flow regulating motor 41 is connected to the control system. The control system can control the rotation direction and rotation angle of the flow regulating motor 41, thereby driving the flow valve stem 431 of the flow regulating valve core 43 to rotate, thereby changing the flow rate of the flow regulating valve core 43 to achieve the purpose of controlling the water output.

[0053] The control system includes a circuit board and a chip. The control system has data acquisition, recording, calculation and display functions of temperature and flow. It can record the warm water temperature measured by the warm water temperature detection device 7, the hot water temperature measured by the hot water temperature detection device 14 and the flow measured by the flow detection device 5, and calculate the required ΔT based on these data. At the same time, the control system also has the function of storing data, and can store multiple groups of different ΔT flow control data in advance. After calculating the value of ΔT, the control system searches for the temperature flow control data or function under the ΔT, and then searches or calculates the water flow according to the temperature in the heating tank 1 at this time, and then controls the flow regulating valve 43 through the flow valve driving unit 4 to adjust the water flow so that the water flow meets the searched or calculated value. On the whole, the flow of the warm water outlet pipe 62 is gradually reduced as the water temperature in the heating tank 1 decreases. This setting not only takes into account the requirements of constant temperature water outlet, but also can better extend the constant temperature water outlet time and enhance the user experience.

[0054] During installation, the cold water inlet pipe 61 of the valve body 2 is connected to the tap water pipeline, and the warm water outlet pipe 62 is connected to one or more water-using devices such as showers or faucets. When the constant temperature water heater is connected to the water circuit and powered on, the control system is immediately started to detect the temperature in the heating tank 1. If the water temperature in the heating tank 1 does not reach the value preset by the control system, the control system controls the heating element 13 to heat the water in the heating tank 1 until the water temperature in the heating element 13 reaches the system preset value. Then the control system controls the heating element 13 to work intermittently to maintain the water temperature in the heating tank 1 at the system preset value.

[0055] When there is no water flow on the cold water inlet pipe 61, the flow detection device 5 cannot detect the water flow, and the control system is in a dormant state; when there is water flow on the cold water inlet pipe 61, the flow detection device 5 transmits a signal to the control system, and the control system starts to work and displays the actual water outlet temperature and flow rate detected. At this time, the user can set the water outlet temperature on the control system. Then the control system can calculate according to the difference between the actual water outlet temperature and the set water outlet temperature, and make the thermostatic valve core 33 rotate quantitatively through the thermostat motor 31, so that the water outlet temperature is the same as the set water outlet temperature.

[0056] At the same time, the control system starts timing and records the water flow measured by the flow detection device 5, the hot water temperature measured by the hot water temperature detection device 14, and the warm water outlet temperature measured by the warm water temperature detection device 7. If the water temperature in the heating tank 1 drops, the temperature difference ΔT between the water inlet temperature and the set water temperature is calculated. After ΔT is obtained, the control system calls the pre-stored data or control function in the system according to the range value of ΔT, and then obtains a corresponding flow value according to the hot water temperature value in the heating tank 1, and then adjusts the actual flow through the flow regulating motor 41 so that the actual flow conforms to the calculated value or the called value. In this process, the outlet water temperature of the warm water outlet pipe 62 will not change, but as the water temperature in the heating tank 1 gradually decreases, the flow rate of the warm water outlet 66 also gradually decreases. This setting can comprehensively consider the requirements of constant temperature water outlet and the user experience. Since the maximum power of the electric heating tank 1 is determined when it is working, if the temperature difference ΔT between the cold water temperature and the set water outlet temperature is large, the heating capacity will not be able to meet the immediate water demand. At this time, the water temperature in the heating tank 1 will gradually decrease. If the water outlet flow is not restricted, the water temperature in the heating tank 1 will drop rapidly, resulting in a shorter overall constant temperature water outlet time. If the water temperature in the heating tank 1 starts to drop, the water outlet flow is limited to a degree that is compatible with the heating capacity of the heating tank 1 (the warm water flow rate multiplied by the temperature rise multiplied by the specific heat capacity of water is equal to the power of the heating tank 1), which will cause the water outlet flow to drop significantly. At this time, although the constant temperature water outlet can be maintained for a long time, it will seriously affect the user experience. The flow of the warm water outlet pipe 62 is gradually reduced as the water temperature in the heating tank 1 drops. On the one hand, it can slow down the speed of the water temperature drop in the heating tank 1, and on the other hand, it can also enable most users to complete bathing under a relatively large water flow.

[0057] If the cold water temperature is relatively high and close to the set water outlet temperature during actual use, and the temperature in the heating tank 1 does not decrease during use, the control system does not limit the flow rate.

[0058] When the faucet is closed, the flow detection device 5 does not sense the water flow, and the control system receives the flow rate as 0, and no longer supplies power to the warm water outlet temperature detection device and receives signals, making it in a disconnected state. At the same time, the control system no longer controls the thermostat motor 31 and the flow regulating motor 41.

[0059] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the protection scope of the present invention. The protection scope of the present invention is determined by the appended claims.

Claims

1. A constant temperature water heater, comprising a heating tank (1), a valve body (2) and a control system, wherein the valve body (2) is provided with a cold water inlet pipe (61), a cold water outlet pipe (63), a hot water inlet pipe (64), a warm water outlet pipe (62) and a cold water branch pipe (222), the cold water inlet pipe (61) and the cold water outlet pipe (63) are connected, and the cold water outlet pipe (63) and the hot water inlet pipe (64) are respectively connected to the water inlet (65) and the water outlet (66) of the heating tank (1); the valve body (2) is provided with a mixing chamber (254), a temperature regulating valve is installed in the mixing chamber (254), the mixing chamber (254) is connected to the hot water inlet pipe (64) and the warm water outlet pipe (62), and the mixing chamber (254) is connected to the cold water inlet pipe (61) through the cold water branch pipe (222), and the characteristics are: A warm water temperature detection device (7) is installed on the warm water outlet pipe (62), and the warm water temperature detection device (7) is connected to a control system. A hot water temperature detection device (14) is arranged in the heating tank (1). A flow detection device (5) and a flow regulating valve (43) are arranged on the valve body (2). The flow regulating valve (43) is transmission-connected to a flow valve driving unit (4). The hot water temperature detection device (14), the flow detection device (5) and the flow valve driving unit (4) are all connected to the control system. A heating element is arranged in the heating tank (1), and flow control data is stored in the control system. When the water temperature in the heating tank continues to drop, the control system calculates the temperature difference between cold water and warm water according to the power of the heating element, the flow detection device, the hot water temperature detection device, and the warm water temperature detection device, and obtains the difference ΔT between the water temperature of the warm water outlet pipe and the water temperature of the cold water inlet pipe. The control system adjusts the flow control valve according to the difference ΔT and refers to the flow control data to control the warm water outlet.

2. The constant temperature water heater according to claim 1, characterized in that: The flow valve driving unit (4) comprises a flow regulating motor (41), a driving gear (44) mounted on an output shaft of the flow regulating motor (41), and a driven gear (42) mounted on a flow valve stem (431) of a flow regulating valve (43), wherein the driving gear (44) and the driven gear (42) are meshed, and the flow regulating motor (41) is a stepping motor or a servo motor.

3. The constant temperature water heater according to claim 1, characterized in that: The temperature regulating valve is a thermostatic valve core (33).

4. The constant temperature water heater according to claim 1, characterized in that: The flow detection device (5) comprises a Hall element (51) and a magnetic rotor (52), wherein the Hall element (51) is arranged outside the valve body (2), and the magnetic rotor (52) is arranged in the flow channel of the cold water inlet pipe (61) or the cold water outlet pipe (63) or the hot water inlet pipe (64) or the warm water outlet pipe (62).

5. The constant temperature water heater according to claim 1, characterized in that: The valve body (2) comprises a water mixing valve body (25) and a cold water valve body (22); a water mixing chamber (254) is arranged in the water mixing valve body (25); a cold water inlet pipe (61), a cold water outlet pipe (63) and a cold water branch pipe (222) are arranged on the cold water valve body (22); and the water mixing chamber (254) is connected to the cold water inlet pipe (61) and the cold water outlet pipe (63) via the cold water branch pipe (222).

6. The constant temperature water heater according to claim 5, characterized in that: The valve body (2) further comprises a hot water valve body (21); a hot water inlet pipe (64) and a warm water outlet pipe (62) are located on the hot water valve body (21); a hot water outlet pipe (212) and a warm water inlet pipe (213) are also provided on the hot water valve body (21); the hot water inlet pipe (64) is connected to a mixing chamber (254) of the mixing valve body (25) via the hot water outlet pipe (212); and the warm water outlet pipe (62) is connected to the mixing chamber (254) of the mixing valve body (25) via the warm water inlet pipe (213).

7. The constant temperature water heater according to claim 6, characterized in that: The cold water valve body (22) and / or the hot water valve body (21) comprises a cavity (221, 211) with an opening at one end, a cold water branch pipe (222) or a hot water outlet pipe (212) being arranged in the cavity (221, 211), one end of the cold water branch pipe (222) or the hot water outlet pipe (212) extending from the closed end of the cavity (221, 211) for communicating with the water mixing valve body (25), and the other end being located in the cavity (221, 211), a plug (26) being arranged at the open end of the cavity (221, 211), and a filter screen (27) being arranged between the plug (26) and the end of the cold water branch pipe (222) and the end of the hot water outlet pipe (212), respectively.

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