A zero-cold-water hot water supply system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2026-08-11
AI Technical Summary
1、零冷水热水供应系统分为两种配置，一种适用于有回水管使用场景，另一种则能够适用于无回水管使用场景，二者不能混用，如果将适用于无回水管使用场景的零冷水热水供应系统应用于有回水管使用场景中，只能将回水管封堵，但会造成回水管内存在死水而影响水质；
[0015]本实用新型的有益效果：一种零冷水热水供应系统，包括热水管道、冷水管道、循环水泵、流量计、控制器以及若干个电控回水器；循环水泵具有进水口、出水口以及回水口，出水口与热水器的冷水进水端连通，回水口与进水口连通，回水口上串接有第一电控阀和第一热电偶；电控回水器与用水终端一一对应；热水管道分别与热水器的热水出水端以及电控回水器的连通；冷水管道分别与进水口以及电控回水器连通；流量计串接在循环水泵的进水口、循环水泵的出水口至热水管道的管路中与控制器电性连接的；控制器与流量计、第一电控阀、第一热电偶以及电控回水器电性连接；通过上述结构能够创新性地支持有回水管与无回水管两种安装场景，无需更换核心部件即可适配新装修预留回水管的房屋、老旧小区无回水管改造项目，大幅提升了系统的适用范围，降低了用户的安装与改造成本，并且能过做到点对点的零冷水热水供应，降低了等待时间以及使用成本。
Smart Images
Figure CN224623187U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water supply systems, and in particular to a zero-cold-water hot water supply system. Background Technology
[0002] In modern residential and commercial hot water supply systems, the zero-cold-water function has become an important requirement for improving user experience. Although traditional zero-cold-water hot water supply systems can use a circulating water pump to drive the cold water in the pipeline to recirculate and heat it, achieving the effect of hot water being available as soon as the water terminal is turned on, this type of zero-cold-water hot water supply system has the following drawbacks: 1. Zero cold water hot water supply system is divided into two configurations: one is suitable for use scenarios with a return water pipe, and the other is suitable for use scenarios without a return water pipe. The two cannot be used interchangeably. If a zero cold water hot water supply system suitable for use scenarios without a return water pipe is applied to use scenarios with a return water pipe, the return water pipe can only be blocked, but this will cause stagnant water in the return water pipe and affect the water quality. 2. Current zero-cold-water hot water supply systems suitable for scenarios with return water pipes cannot achieve point-to-point zero-cold-water supply. Each zero-cold-water circulation can only be completed by running through the entire return water pipe. When used in large-sized residences such as apartments and villas, this will greatly increase the length of the pipeline and the cost of use. In particular, when the hot water source is an air source heat pump, the zero-cold-water operation will consume a large amount of the stored hot water, resulting in a lot of waste.
[0003] Therefore, there is an urgent need for a zero-cold-water hot water supply system to solve the above problems. Utility Model Content
[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a zero-cold-water hot water supply system.
[0005] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: a zero cold water hot water supply system, including hot water pipes, cold water pipes, circulating water pumps, flow meters, controllers, and several electrically controlled return water devices; The circulating water pump has an inlet, an outlet and a return outlet. The outlet is connected to the cold water inlet of the water heater, and the return outlet is connected to the inlet. A first electric control valve and a first thermocouple are connected in series on the return outlet. Each electrically controlled water return device corresponds to a specific water-using terminal. The hot water pipes are connected to the hot water outlet of the water heater and the electrically controlled return water device, respectively. The cold water pipes are connected to the water inlet and the electrically controlled return water device, respectively. The flow meter is connected in series in the pipeline from the inlet of the circulating water pump and the outlet of the circulating water pump to the hot water pipe and is electrically connected to the controller. The controller is electrically connected to the flow meter, the first electrically controlled valve, the first thermocouple, and the electrically controlled water return device; When the return water inlet is connected to the return water pipe, the controller can start the circulating water pump, open the first solenoid valve, and after the flow meter detects a continuous signal that meets the requirements, the water in the hot water pipe will enter the return water inlet through the return water pipe until the first thermocouple detects that the water temperature has reached the preset value. Then the controller will stop the circulating water pump and close the first solenoid valve. When the return water outlet is not connected to the return water pipe, the controller can start the circulating water pump and open the first electrically controlled valve when it receives the first zero cold water operation control signal. After the flow meter does not detect a continuous signal that meets the requirements, the controller controls the first electrically controlled valve to close and controls the electrically controlled return water device to start, so that the water in the hot water pipe enters the cold water pipe through the electrically controlled return water device until the electrically controlled return water device detects that the water temperature has reached the preset value. Then the controller controls the circulating water pump to stop and the electrically controlled return water device to close. When the return water outlet is not connected to the return water pipe, the controller can control the circulation water pump to start, control the first electrically controlled valve to open, and control the electrically controlled return water device to start when it receives the second zero cold water operation signal, so that the water in the hot water pipe enters the cold water pipe through the electrically controlled return water device until the electrically controlled return water device detects that the water temperature has reached the preset value, at which point the controller controls the circulation water pump to stop and the electrically controlled return water device to close.
[0006] In one of the preferred embodiments of this utility model, a first electrically controlled valve is connected in series at the end of the return water port near the inlet of the circulating water pump, a first thermocouple is connected in series between the return water port and the inlet of the circulating water pump, and a first check valve is connected in series at the return water port between the first electrically controlled valve and the first thermocouple.
[0007] In one of the preferred embodiments of this utility model, the first electrically controlled valve is configured as a motor valve.
[0008] In one of the preferred embodiments of this utility model, the first electrically controlled valve is configured as a solenoid valve.
[0009] As one of the preferred embodiments of this utility model, the electrically controlled water return device has a hot water pipe, a cold water pipe and a bypass pipe; Hot water pipes are connected in series with hot water pipes, and cold water pipes are connected in series with cold water pipes; The bypass pipes are connected to the hot water pipes and the cold water pipes respectively; A second electrically controlled valve is connected in series on the bypass pipe, and a second thermocouple is connected in series on the hot water pipe. The second electrically controlled valve and the second thermocouple are electrically connected to the controller. When the controller receives a zero-cold-water operation signal, it can control the circulating water pump to start and control the second electrically controlled valve to open, so that the water in the hot water pipe enters the cold water pipe through the hot water pipe, bypass pipe, and cold water pipe, until the second thermocouple detects that the water temperature has reached the preset value.
[0010] As one of the preferred embodiments of this utility model, a second check valve is connected in series on the bypass pipe between the second thermocouple and the second electrically controlled valve, so that water can enter the cold water pipe from the hot water pipe through the bypass pipe.
[0011] In one of the preferred embodiments of this utility model, the second electrically controlled valve is configured as a motor valve or a solenoid valve.
[0012] As one of the preferred embodiments of this utility model, the controller includes a first control module and a second control module electrically connected via wireless or wired communication. The first control module is electrically connected to the electrically controlled water return device, and the second control module is electrically connected to the circulating water pump, the first electrically controlled valve, and the first thermocouple.
[0013] As one of the preferred embodiments of this utility model, the first control module and the electrically controlled return water device are designed separately, and the second control module and the circulating water pump are designed separately.
[0014] As one of the preferred embodiments of this utility model, the first control module and the electric control return water device are integrated into one unit, and the second control module and the circulating water pump are integrated into one unit.
[0015] The beneficial effects of this utility model are as follows: A zero-cold-water hot water supply system includes hot water pipes, cold water pipes, a circulating water pump, a flow meter, a controller, and several electrically controlled return water devices; the circulating water pump has an inlet, an outlet, and a return water outlet, the outlet being connected to the cold water inlet of the water heater, and the return water outlet being connected to the inlet, with a first electrically controlled valve and a first thermocouple connected in series on the return water outlet; each electrically controlled return water device corresponds to a water-using terminal; the hot water pipes are connected to the hot water outlet of the water heater and the electrically controlled return water devices respectively; the cold water pipes are connected to the inlet and the electrically controlled return water devices respectively; the flow meter is connected in series with the circulating water pump. The controller is electrically connected to the inlet of the circulating water pump, the outlet of the circulating water pump, and the hot water pipe. The controller is electrically connected to the flow meter, the first electrically controlled valve, the first thermocouple, and the electrically controlled return water device. This structure innovatively supports two installation scenarios: with and without a return water pipe. It can be adapted to newly renovated houses with pre-installed return water pipes and old residential areas without return water pipe renovation projects without replacing core components. This greatly improves the applicability of the system, reduces the installation and renovation costs for users, and can achieve point-to-point supply of cold and hot water, reducing waiting time and operating costs. Attached Figure Description
[0016] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a zero-cold-water hot water supply system in normal use without a return water pipe. Figure 2 This is a schematic diagram of a zero-cold-water hot water supply system in operation without a return water pipe and with zero cold water supply. Figure 3 This is a schematic diagram of a zero-cold-water hot water supply system in normal use with the return water pipe connected. Figure 4 This is a first schematic diagram of a zero-cold-water hot water supply system in a state of connection to the return water pipe and zero-cold-water operation. Figure 5 This is a second schematic diagram of a zero-cold-water hot water supply system in the state of connected return water pipe and zero-cold-water operation. Detailed Implementation
[0017] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.
[0018] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. Any mention of "second" is for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0019] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0020] In this utility model, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.
[0021] Reference Figures 1-5A zero-cold-water hot water supply system includes a hot water pipe 10, a cold water pipe 20, a circulating water pump 30, a flow meter 74, a controller 40, and several electrically controlled return water devices 50. The circulating water pump 30 has an inlet 31, an outlet 32 and a return outlet 33. The outlet 32 is connected to the cold water inlet 61 of the water heater 60, and the return outlet 33 is connected to the inlet 31. A first electric control valve 71 and a first thermocouple 72 are connected in series on the return outlet 33. Each electrically controlled water return device 50 corresponds one-to-one with a water terminal 80. Hot water pipe 10 is connected to the hot water outlet 62 of water heater 60 and the electrically controlled return water device 50 respectively; The cold water pipe 20 is connected to the water inlet 31 and the electrically controlled return water device 50 respectively; The flow meter 74 is connected in series in the pipeline from the inlet 31 and outlet 32 of the circulating water pump 30 to the hot water pipe 10 and is electrically connected to the controller 40. The controller 40 is electrically connected to the flow meter 74, the first electrically controlled valve 71, the first thermocouple 72, and the electrically controlled water return device 50. When the return water inlet 33 is connected to the return water pipe 90, the controller 40 can control the circulating water pump 30 to start, the first solenoid valve 71 to open, and the flow meter 74 to detect a continuous signal that meets the requirements, so that the water in the hot water pipe 10 enters the return water inlet 33 through the return water pipe 90 until the first thermocouple 72 detects that the water temperature has reached the preset value. Then the controller 40 controls the circulating water pump 30 to stop and the first solenoid valve 71 to close. When the return water inlet 33 is not connected to the return water pipe 90, the controller 40 can control the circulating water pump 30 to start, the first solenoid valve 71 to open, and the flow meter 74 to close the first solenoid valve 71 and start the solenoid return water device 50 when it receives the first zero cold water operation control signal. This allows the water in the hot water pipe 10 to enter the cold water pipe 20 through the solenoid return water device 50 until the solenoid return water device 50 detects that the water temperature has reached the preset value. Then, the controller 40 controls the circulating water pump 30 to stop and the solenoid return water device 50 to close. When the return water inlet 33 is not connected to the return water pipe 90, the controller 40 can control the circulating water pump 30 to start and the electronically controlled return water device 50 to start when it receives the second zero cold water operation signal, so that the water in the hot water pipe 10 enters the cold water pipe 20 through the electronically controlled return water device 50 until the electronically controlled return water device 50 detects that the water temperature has reached the preset value, the controller 40 controls the circulating water pump 30 to stop and the electronically controlled return water device 50 to close.
[0022] The working principle of this utility model is as follows: 1) Reference Figures 1-2This is a schematic diagram of a zero-cold-water hot water supply system applied in a scenario without a return water pipe. Figure 1 This is a schematic diagram of a zero-cold-water hot water supply system in normal operation without a return water pipe. The first solenoid valve 71 is configured as a motor valve or a solenoid valve. In some embodiments, the first solenoid valve 71 is connected in series at the end of the return water port 33 near the inlet 31 of the circulating water pump 30. The first thermocouple 72 is connected in series between the return water port 33 and the inlet 31 of the circulating water pump 30. A first check valve 73 is connected in series on the return water port 33 between the first solenoid valve 71 and the first thermocouple 72. The first check valve 73 ensures that water can only enter the circulating water pump 30 from the return water pipe 90 through the return water port 33 for circulation, and cannot flow in the opposite direction.
[0023] When the valve of the water terminal 80 (such as a hardware faucet) is opened, the hot water in the hot water pipe 10 and the cold water in the cold water pipe 20 are mixed through the control valve and released from the water terminal 80 for the user's use. The temperature can be adjusted by regulating the mixing ratio through the control valve.
[0024] Reference Figure 2 When the controller 40 receives the first zero-cold-water operation control signal, it controls the circulating water pump 30 to start, the first electrically controlled valve 71 to open, and after the flow meter 74 does not detect a continuous signal that meets the requirements, the controller 40 controls the first electrically controlled valve 71 to close and the electrically controlled return water device 50 to start, so that the water in the hot water pipe 10 enters the cold water pipe 20 through the electrically controlled return water device 50 until the electrically controlled return water device 50 detects that the water temperature has reached the preset value, and the user can use it with confidence. After the zero-cold-water operation is completed, the controller 40 controls the circulating water pump 30 to stop and the electrically controlled return water device 50 to close, realizing point-to-point zero-cold-water hot water supply.
[0025] Reference Figure 2 When the controller 40 receives the second zero-cold-water operation signal, it can control the circulating water pump 30 to start and the electrically controlled return water device 50 to start, so that the water in the hot water pipe 10 enters the cold water pipe 20 through the electrically controlled return water device 50. The zero-cold-water operation is completed when the electrically controlled return water device 50 detects that the water temperature has reached the preset value. The controller 40 controls the circulating water pump 30 to stop and the electrically controlled return water device 50 to close, so as to realize point-to-point zero-cold-water hot water supply.
[0026] The first zero-cold-water operation control signal is a control signal that the controller 40 directly controls the circulating water pump 30, and the second zero-cold-water operation control signal is a control signal that the controller 40 controls the circulating water pump 30 and at least one electrically controlled return water device 50.
[0027] Furthermore, in some buildings, based on usage frequency and cost considerations, it is not necessary to install an electrically controlled recirculating water device 50 for every water terminal 80. Usually, an electrically controlled recirculating water device 50 is installed at the water terminal 80 furthest from the inlet water pipe. In this case, the entire water supply system can achieve zero cold water and hot water supply. According to the distance from the inlet water pipe from near to far, the electrically controlled recirculating water devices 50 are numbered 501, 502, 503, 504, 505...50n. When the system is equipped with multiple electrically controlled recirculating water devices 50, point-to-point zero cold water small circulation can be achieved by controlling the start and stop of each electrically controlled recirculating water device 50.
[0028] 2) Reference Figures 3-5 This is a schematic diagram of a zero-cold-water hot water supply system applied in a scenario with a return water pipe. One end of the return water pipe 90 is connected to the end of the hot water pipe 10, and the other end is connected to the return water inlet 33. Figure 3 This is a schematic diagram of a zero-cold-water hot water supply system in normal use with the return water pipe connected. When the valve of the water terminal 80 (e.g., a hardware faucet) is opened, the hot water in the hot water pipe 10 and the cold water in the cold water pipe 20 are mixed through the control valve and released from the water terminal 80 for the user. The temperature can be adjusted by regulating the mixing ratio through the control valve.
[0029] Reference Figure 5 This is a schematic diagram of a zero-cold-water hot water supply system in the state of connection to the return water pipe and large-circulation zero-cold-water operation. When the controller 40 receives the first zero-cold-water operation control signal, it controls the circulation pump 30 to start, the first solenoid valve 71 to open, and the flow meter 74 to detect a continuous signal that meets the requirements, so that the water in the hot water pipe 10 enters the return port 33 through the return water pipe 90 until the first thermocouple 72 detects that the water temperature reaches the preset value. Then, the controller 40 controls the circulation pump 30 to stop and the first solenoid valve 71 to close, indicating that the water in the return water pipe 90 has been completely circulated out and the large-circulation zero-cold-water operation is completed. The controller 40 then controls the circulation pump 30 and the first solenoid valve 71 to close, realizing the large-circulation zero-cold-water hot water supply.
[0030] Reference Figure 4 This is a schematic diagram of the zero-cold-water hot water supply system in point-to-point zero-cold-water operation mode with the return water pipe connected. It controls the starting of the circulating water pump 30, the closing of the first electrically controlled valve 71, and the starting of the electrically controlled return water device 50. The electrically controlled return water device 50 connects the hot water pipe 10 and the cold water pipe 20, so that the water in the hot water pipe 10 enters the cold water pipe 20 through the electrically controlled return water device 50 until the electrically controlled return water device 50 detects that the water temperature has reached the preset value, indicating that the water temperature of the current water terminal 80 has reached the preset value and the user can use it with confidence. The zero-cold-water operation is completed, and the controller 40 controls the circulating water pump 30 and the electrically controlled return water device 50 to close, realizing point-to-point zero-cold-water hot water supply.
[0031] 3) Reference Figures 1-5 In some embodiments, the electrically controlled return water device 50 has a hot water pipe 51, a cold water pipe 52, and a bypass pipe 53; the hot water pipe 51 is connected in series to the hot water pipe 10, and the cold water pipe 52 is connected in series to the cold water pipe 20; the bypass pipe 53 is connected to both the hot water pipe 51 and the cold water pipe 52; a second electrically controlled valve 75 is connected in series to the bypass pipe 53, wherein the second electrically controlled valve 75 is configured as a motor valve or a solenoid valve; a second thermocouple 76 is connected in series to the hot water pipe 51, and the second electrically controlled valve 75 and the second thermocouple 76 are electrically connected to the controller 40; the controller 40 can receive zero When the cold water operation signal is received, the controller controls the circulating water pump 30 to start and the second solenoid valve 75 to open, so that the water in the hot water pipe 10 enters the cold water pipe 20 through the hot water pipe 51, the bypass pipe 53, and the cold water pipe 52, thereby circulating the cold water in the hot water pipe 10 back into the cold water pipe 20. When the second thermocouple 76 detects that the water temperature has reached the preset value, it means that all the cold water in the hot water pipe 10 has been circulated out, and the user can use it with confidence. After the zero cold water operation is completed, the controller 40 controls the circulating water pump 30 and the second solenoid valve 75 to close, realizing point-to-point zero cold water and hot water supply.
[0032] 4) Reference Figures 1-5 In some embodiments, a second check valve 77 is connected in series on the bypass pipe 53 between the second thermocouple 76 and the second electrically controlled valve 75. The second check valve 77 allows water to flow only from the hot water pipe 51 into the cold water pipe 52 via the bypass pipe 53, and prevents it from flowing in the opposite direction.
[0033] 5) Reference Figures 1-5 In some embodiments, the controller 40 includes a first control module 41 and a second control module 42 electrically connected via wireless or wired communication. The first control module 41 is electrically connected to the electrically controlled water return device 50, and the second control module 42 is electrically connected to the circulating water pump 30, the first electrically controlled valve 71, and the first thermocouple 72. Preferably, the first control module 41 and the electrically controlled water return device 50 are separate designs, and the second control module 42 and the circulating water pump 30 are separate designs. Of course, the first control module 41 and the electrically controlled water return device 50 can also be integrated, and the second control module 42 and the circulating water pump 30 can also be integrated.
[0034] The advantages of this utility model are: the above structure can innovatively support two installation scenarios, one with a return water pipe and the other without. It can be adapted to newly renovated houses with pre-installed return water pipes and old community renovation projects without return water pipes without replacing core components, which greatly improves the applicability of the system, reduces the installation and renovation costs for users, and can achieve point-to-point supply of cold and hot water, reducing waiting time and usage costs.
[0035] Of course, this utility model is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of this utility model. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.
Claims
1. A zero cold water hot water supply system characterised in that: It includes hot water pipes (10), cold water pipes (20), circulating water pumps (30), flow meters (74), controllers (40) and several electrically controlled return water devices (50). The circulating water pump (30) has an inlet (31), an outlet (32) and a return outlet (33). The outlet (32) is connected to the cold water inlet (61) of the water heater (60). The return outlet (33) is connected to the inlet (31). A first electric control valve (71) and a first thermocouple (72) are connected in series on the return outlet (33). The electrically controlled water return device (50) corresponds one-to-one with the water terminal (80); The hot water pipe (10) is connected to the hot water outlet (62) of the water heater (60) and the electronically controlled return water device (50) respectively; The cold water pipe (20) is connected to the water inlet (31) and the electrically controlled return water device (50) respectively; The flow meter (74) is connected in series in the pipeline from the inlet (31) of the circulating water pump (30), the outlet (32) of the circulating water pump (30) to the hot water pipe (10) and is electrically connected to the controller (40). The controller (40) is electrically connected to the flow meter (74), the first electrically controlled valve (71), the first thermocouple (72), and the electrically controlled water return device (50); When the return water inlet (33) is connected to the return water pipe (90), the controller (40) can, upon receiving the first zero cold water operation control signal, control the circulating water pump (30) to start, the first electric control valve (71) to open, and the flow meter (74) to detect a continuous signal that meets the requirements, so that the water in the hot water pipe (10) enters the return water inlet (33) through the return water pipe (90) until the first thermocouple (72) detects that the water temperature has reached the preset value, and the controller (40) controls the circulating water pump (30) to stop and the first electric control valve (71) to close. When the return water inlet (33) is not connected to the return water pipe (90), the controller (40) can control the circulating water pump (30) to start, the first electric control valve (71) to open, and the flow meter (74) to not detect a continuous signal that meets the requirements when it receives the first zero cold water operation control signal. Then, the controller (40) controls the first electric control valve (71) to close and controls the electric return water device (50) to start, so that the water in the hot water pipe (10) enters the cold water pipe (20) through the electric return water device (50) until the electric return water device (50) detects that the water temperature reaches the preset value. Then, the controller (40) controls the circulating water pump (30) to stop and the electric return water device (50) to close. When the return water inlet (33) is not connected to the return water pipe (90), the controller (40) can control the circulating water pump (30) to start and control the electric return water device (50) to start when it receives the second zero cold water operation signal, so that the water in the hot water pipe (10) enters the cold water pipe (20) through the electric return water device (50) until the electric return water device (50) detects that the water temperature reaches the preset value, the controller (40) controls the circulating water pump (30) to stop and the electric return water device (50) to close.
2. A cold water bypass hot water supply system as claimed in claim 1, wherein: The first solenoid valve (71) is connected in series at the end of the return water port (33) near the inlet (31) of the circulating water pump (30). The first thermocouple (72) is connected in series between the return water port (33) of the circulating water pump (30) and the inlet (31) of the circulating water pump (30). A first check valve (73) is connected in series on the return water port (33) between the first solenoid valve (71) and the first thermocouple (72).
3. The zero-cold-water hot water supply system according to claim 1, characterized in that: The first electrically controlled valve (71) is configured as a motor valve.
4. A zero-cold-water hot water supply system according to claim 1, characterized in that: The first electrically controlled valve (71) is configured as a solenoid valve.
5. A zero-cold-water hot water supply system according to claim 1, characterized in that: The electrically controlled water return device (50) has a hot water pipe (51), a cold water pipe (52) and a bypass pipe (53). The hot water pipe (51) is connected in series to the hot water pipe (10), and the cold water pipe (52) is connected in series to the cold water pipe (20); The bypass pipe (53) is connected to the hot water pipe (51) and the cold water pipe (52) respectively; A second electrically controlled valve (75) is connected in series on the bypass pipeline (53), and a second thermocouple (76) is connected in series on the hot water pipeline (51). The second electrically controlled valve (75) and the second thermocouple (76) are electrically connected to the controller (40). The controller (40) can control the circulating water pump (30) to start and control the second electrically controlled valve (75) to open when it receives a zero cold water operation signal, so that the water in the hot water pipe (10) enters the cold water pipe (20) through the hot water pipe (51), bypass pipe (53), and cold water pipe (52) until the second thermocouple (76) detects that the water temperature has reached the preset value.
6. A zero-cold-water hot water supply system according to claim 5, characterized in that: A second check valve (77) is connected in series on the bypass pipe (53) between the second thermocouple (76) and the second electrically controlled valve (75) so that water can enter the cold water pipe (52) from the hot water pipe (51) through the bypass pipe (53).
7. A zero-cold-water hot water supply system according to claim 5, characterized in that: The second electrically controlled valve (75) is configured as a motor valve or a solenoid valve.
8. A zero-cold-water hot water supply system according to claim 1, characterized in that: The controller (40) includes a first control module (41) and a second control module (42) electrically connected via wireless or wired communication. The first control module (41) is electrically connected to the electrically controlled water return device (50), and the second control module (42) is electrically connected to the circulating water pump (30), the first electrically controlled valve (71), and the first thermocouple (72).
9. A zero-cold-water hot water supply system according to claim 8, characterized in that: The first control module (41) and the electrically controlled water return device (50) are designed separately, and the second control module (42) and the circulating water pump (30) are designed separately.
10. A zero-cold-water hot water supply system according to claim 8, characterized in that: The first control module (41) and the electrically controlled water return device (50) are integrated into one unit, and the second control module (42) and the circulating water pump (30) are integrated into one unit.