Intelligent temperature control evaporation system of hand-washing table based on concentrated hot return water waste heat

Abstract

The application relates to a hand-washing table intelligent temperature control evaporation system based on concentrated hot return water waste heat, which is suitable for the technical field of building water supply and drainage and building energy-saving control. The technical scheme of the application is as follows: a hand-washing table intelligent temperature control evaporation system based on concentrated hot return water waste heat, which comprises a hand-washing table heating loop arranged in the interior of a hand-washing table body, the input and output ends of the hand-washing table heating loop being connected with a hot return water main pipe of a building concentrated hot water supply system through hot return water branches; a temperature control system, which comprises at least one temperature sensor for detecting the temperature of the hand-washing table body, an adjustable opening degree temperature control valve arranged on the hot return water branch, at least one event trigger for generating a trigger signal when the hand-washing table is used or the table top is wet, at least one water stain detection device for detecting the wet state of the table top of the hand-washing table, and a main controller connected with the temperature sensor, the temperature control valve and the event trigger, respectively.

Description

Technical Field

[0001] This invention relates to an intelligent temperature-controlled evaporation system for handwashing basins based on waste heat from centralized hot water return. It is applicable to the fields of building water supply and drainage and building energy-saving control technology. Background Technology

[0002] In public buildings such as hospitals, shopping malls, and office buildings, centralized hot water supply systems typically include hot water return pipes to maintain a stable hot water temperature at the end of the network. During long-term operation, the hot water return carries stable but unrecovered low-grade heat energy, which is largely lost passively through heat dissipation from the pipes.

[0003] After frequent use, water stains are easily left on the surface of washbasins, especially in public buildings such as hospitals, hotels, and transportation hubs. Due to the high frequency of use and high humidity, the water stains evaporate slowly, easily forming watermarks and scale, which accelerates the growth and reproduction of bacteria, affecting hygiene and visual appearance.

[0004] In existing technologies, manual wiping or enhanced ventilation are commonly used to accelerate the drying of washbasin surfaces, but these methods suffer from high labor costs and additional energy consumption. Current technologies for utilizing waste heat from hot water return systems are mostly concentrated in heating or domestic hot water preheating, and there is a lack of refined, temperature-controlled application solutions specifically for scenarios involving water evaporation from washbasin surfaces. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a smart temperature-controlled evaporation system for handwashing basins based on the waste heat of centralized hot water return, in order to address the above-mentioned problems.

[0006] The technical solution adopted in this invention is: a smart temperature-controlled evaporation system for handwashing basins based on centralized hot water return waste heat, comprising: The handwashing basin heating circuit is located inside the handwashing basin body, and its input and output ends are connected to the main hot water return pipe of the building's centralized hot water supply system via hot water return branches. The temperature control system includes at least one temperature sensor for detecting the temperature of the washbasin body, an adjustable temperature control valve disposed on the hot water return branch, at least one event trigger for generating a trigger signal when the washbasin is used or the surface is wet, at least one water stain detection device for detecting the wet surface of the washbasin, and a main controller that is connected to the temperature sensor, the temperature control valve, and the event trigger signal respectively. The main controller is configured as follows: Upon receiving the trigger signal from the event trigger, the system being powered on for the first time, or reaching the preset start-up time, the temperature control valve is opened to its minimum opening and the heating process is initiated. The opening of the temperature control valve is adjusted based on the real-time temperature collected by the temperature sensor, so that the temperature of the washbasin body is maintained within the preset evaporation target temperature range. When the water stain detection device detects that the table surface has reached a preset dry state, the heating duration has reached a preset upper limit, or the preset shutdown time has been reached, the temperature control valve is closed or reduced to the minimum opening degree and the heating process is ended.

[0007] Through the above-mentioned technical means, the low-grade waste heat of the centralized hot water return water, which was originally passively lost, is directed into the internal heating circuit of the washbasin, so that the countertop can be heated without additional heating energy. The main controller realizes automatic start and stop under multiple conditions and closed-loop temperature regulation, which not only ensures rapid evaporation of water stains, but also avoids ineffective heating and the risk of overheating. This solves the problems of waste heat, high consumption and low efficiency of drying methods, and lack of safe temperature control in the existing technology.

[0008] As a preferred embodiment, the pipe cross-section of the handwashing basin heating circuit is smaller than the pipe cross-section of the hot water return main pipe, so that the flow rate of hot water flowing through the handwashing basin heating circuit is hydraulically self-limited under the pressure difference of the centralized hot water return system.

[0009] Through the above-mentioned technical means and the hydraulic self-limiting flow design, only a small amount of hot water is diverted, without disrupting the hydraulic balance of the original centralized hot water return system, thus avoiding affecting the normal hot water supply of the building.

[0010] As a preferred embodiment, the washbasin body is provided with a heat conduction channel inside, and the washbasin heating circuit is embedded in the heat conduction channel and forms an integral heat exchange structure with the washbasin body.

[0011] By employing the aforementioned technical means, the heating circuit is made to fit tightly against the washbasin body, eliminating the thermal resistance caused by air gaps, achieving efficient and uniform heat transfer, improving the surface heating speed and temperature uniformity, and ensuring the evaporation effect of water stains.

[0012] As a preferred embodiment, the handwashing basin heating circuit has a serpentine, ring, or multi-loop structure to increase the contact area with the handwashing basin body.

[0013] By using the above-mentioned technical means, the heat exchange area between the heating circuit and the tabletop is maximized, so that the heat is evenly distributed across the entire tabletop, avoiding local overheating or uneven temperature, and further improving the uniformity and efficiency of water stain evaporation.

[0014] As a preferred embodiment, the heating circuit of the washbasin is provided with an insulation layer on the side away from the washbasin body.

[0015] By employing the aforementioned technical means, heat loss from the heating circuit to the non-countertop direction is blocked, allowing residual heat to be concentrated for countertop heating and improving the utilization rate of residual heat; at the same time, condensation is prevented on the back of the heating circuit, avoiding dampness and bacterial growth on the wall and ensuring fire safety.

[0016] As a preferred embodiment, the temperature control valve is a fail-close valve, which automatically closes the hot water return branch when the main controller malfunctions, the power supply is interrupted, or the control signal is lost.

[0017] By employing the aforementioned technical means, the residual heat supply is automatically cut off when the system malfunctions, preventing the handwashing station from overheating at the hardware level, avoiding burns to users or damage to the equipment, constructing a passive safety protection mechanism, and improving system reliability.

[0018] As a preferred embodiment, the water stain detection device includes an image acquisition unit and an image processing unit. The image acquisition unit acquires images of the washbasin countertop, and the image processing unit analyzes the washbasin countertop images to identify water stain distribution, reflection characteristics, or wet areas on the surface, and determines whether the washbasin countertop is in a dry state.

[0019] By employing the aforementioned technical means, machine vision technology is used to accurately identify the distribution and state of water stains on the countertop, achieving non-contact detection in a dry state. This method has a wide detection range and high accuracy, providing a reliable basis for the system to automatically shut down.

[0020] As a preferred embodiment, the water stain detection device includes a humidity sensor, a capacitive water film sensor, a resistive water stain sensor, or a conductive water film detection unit, used to detect humidity changes on or near the washbasin countertop.

[0021] As a preferred embodiment, the event trigger can generate the usage trigger signal based on water usage behavior, human and operational perception, or feedback signals from the water stain detection device.

[0022] As a preferred embodiment, when the event trigger generates the usage trigger signal based on water usage behavior, it includes a flow sensor or water flow switch installed on the water inlet pipe of the sink. When water flow is detected in the water inlet pipe of the sink, the usage trigger signal is generated.

[0023] By using the above-mentioned technical means, the water usage at the washbasin is directly detected, and the system is triggered to start the moment the user turns on the faucet, so as to realize the early intervention of heating and shorten the evaporation time of water stains.

[0024] As a preferred embodiment, when the event trigger generates the use trigger signal based on human body and operation perception, including but not limited to at least one of infrared sensors, millimeter-wave radar sensors, pressure sensors, photoelectric sensors or touch switches, it is used to detect the user's behavior of approaching, touching or operating the handwashing station, and generate the use trigger signal.

[0025] By using the aforementioned technical means, the system detects the user's interaction with the handwashing station and triggers the system when the user is about to use or is using the handwashing station, thereby further improving the response speed and adapting to different usage habits.

[0026] As a preferred embodiment, the event trigger responds based on the feedback signal of the water stain detection device, and generates the use trigger signal when the water stain detection device detects that the washbasin countertop is wet.

[0027] The beneficial effects of this invention are as follows: By branching a normally open hot water return branch from the centralized hot water return main, the invention efficiently transfers the residual heat of the return water to the washbasin body, achieving evaporation of surface water stains. No additional heating equipment is required; the system fully utilizes its existing thermal energy. It is activated by a trigger signal and can shut down the intelligent temperature-controlled evaporation system when the washbasin surface is detected to be dry, the heating duration reaches a preset time, or a preset shutdown time is reached. This reduces building operating energy consumption and meets the requirements of green building and energy-saving design.

[0028] This invention uses a temperature sensor to collect the temperature of the washbasin body in real time, and the control unit automatically adjusts the opening of the temperature control valve to keep the temperature of the washbasin within the target evaporation range. This ensures that surface water evaporates quickly while avoiding excessive surface temperature that could cause burns or damage to the equipment, thus achieving intelligent closed-loop regulation.

[0029] In this invention, the temperature control system is independently controlled from the building's centralized hot water supply system, without affecting the main return water condition. It supports closed-loop control functions such as valve drive units, logic judgment units, and timing units, achieving safe, reliable, and automated temperature control and evaporation functions. It is suitable for various scenarios such as public buildings, schools, hospitals, and office buildings. The branch pipes and heating circuits have rationally designed friction and local resistance, allowing the flow rate of hot return water through the heating circuit to be self-limited. This avoids disrupting the hydraulic balance of the original centralized hot water return system without adding independent booster equipment, ensuring the overall stable operation of the system.

[0030] This invention improves hygiene and user comfort by maintaining the evaporation of moisture on the surface of the handwashing station, reducing residual water stains, lowering the risk of bacterial growth, reducing the frequency of manual wiping and cleaning, and enhancing the level of intelligent management of public buildings. Attached Figure Description

[0031] Figure 1 This is an isometric overview of the intelligent temperature-controlled evaporation system for handwashing basins based on the waste heat of centralized hot water return, according to the present invention.

[0032] Figure 2 This is a component disassembly diagram of the system of the present invention.

[0033] Figure 3 This is a schematic diagram of the main controller of the present invention.

[0034] Figure 4 This is a plan view of the heating circuit of the handwashing station of the present invention.

[0035] Figure 5 This is a schematic diagram of the control method of the system of the present invention.

[0036] The markings in the diagram are as follows: 11-Hot water return main pipe, 12-Hot water return branch, 21-Washbasin body, 22-Washbasin heating circuit, 23-Heat conduction channel, 24-Insulation layer, 31-Temperature sensor, 32-Temperature control valve, 33-Main controller, 34-Signal line, 35-Event trigger, 36-Water stain detection device. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0038] This embodiment provides a smart temperature-controlled evaporation system for a handwashing station based on the waste heat of centralized hot water return, including a centralized hot water supply system, a handwashing station, and a temperature control system.

[0039] In this example, the centralized hot water supply system includes the building's original hot water return main 11 and two normally open hot water return branches 12 connected to the hot water return main 11. The hot water return main 11 continuously circulates hot water return carrying low-grade waste heat. The hot water return branches 12 are used to transport a small portion of the hot water in the main to the sink heating circuit 22 on the sink, and then return to the hot water return main 11 via another hot water return branch 12.

[0040] In this embodiment, the washbasin includes a washbasin body 21, a washbasin heating circuit 22, a heat conduction channel 23, and an insulation layer 24. The washbasin body 21 is a ceramic or stone countertop commonly used in public buildings, and has a pre-fabricated heat conduction channel 23 inside. The washbasin heating circuit 22 is embedded in the heat conduction channel 23, forming an integral heat exchange structure with the washbasin body 21. Its input and output ends are respectively connected to two hot water return branches 12, forming a closed waste heat circulation loop.

[0041] In this example, the sink heating circuit 22 uses copper tubing, which has excellent thermal conductivity. Its structure is a serpentine arrangement with a 50mm spacing between heating circuits and a 25mm spacing from the side wall or sink opening, maximizing the contact area with the sink body 21. The pipe cross-section of the heating circuit 22 is a 10mm × 5mm rectangle, much smaller than the DN25 (approximately 20mm inner diameter) of the hot water return main pipe 11, allowing the hot water flow through the heating circuit 22 to be hydraulically self-limited under the pressure difference of the centralized hot water return system.

[0042] In this embodiment, the heating circuit 22 is covered with an insulation layer 24 on the side away from the washbasin body 21. The insulation layer is made of rubber and plastic and is 20mm thick. It has the characteristics of low thermal conductivity, moisture resistance, anti-condensation and good fire resistance, which can effectively block heat loss to the non-counter surface.

[0043] In this embodiment, the temperature control system 3 is a local control system that operates independently of the centralized hot water supply system control system, including a temperature sensor 31, a temperature control valve 32, a main controller 33, a signal line 34, an event trigger 35, and a water stain detection device 36.

[0044] In this example, temperature sensor 31 is installed inside the washbasin body 21 at a distance from the surface, thermally coupled to the washbasin body, and is used to collect the surface temperature T1 in real time. Temperature control valve 32 is an electrically adjustable ball valve, installed on one of the hot water return branches 12, and is a fail-close type valve. When the main controller 33 malfunctions, power is interrupted, or the control signal is lost, the valve automatically closes the hot water return branch 12 to prevent the surface from overheating. Event trigger 35 uses a combination of an infrared human body sensor and a flow sensor on the washbasin's water inlet pipe. The infrared sensor is installed above the washbasin to detect user approach; the flow sensor is installed on the cold and hot water inlet pipes of the washbasin to detect water flow. When either sensor detects a corresponding signal, a trigger signal is generated and sent to the main controller 33.

[0045] The water stain detection device 36 employs a combination of a capacitive water film sensor and an image acquisition unit. The capacitive water film sensor is installed in the water-prone area of ​​the washbasin countertop to detect surface water film; the image acquisition unit uses a miniature camera, installed above the washbasin, and works with the image processing unit to identify the distribution and reflection characteristics of water stains on the countertop. The main controller 33 comprehensively judges the dryness of the countertop based on the signals from the two detection devices, improving the accuracy of the judgment.

[0046] In this embodiment, the main controller 33 integrates a logic judgment unit, a valve drive unit, and a timing unit. The logic judgment unit is used to compare the collected temperature with a preset threshold and generate valve control commands and heating process start / stop commands; the valve drive unit adopts an electric servo drive, which can precisely adjust the opening of the temperature control valve 32; the timing unit is used for system timed start / stop, valve action delay timing, and heating duration upper limit control.

[0047] In this embodiment, the main controller 33 is configured as follows: S1. Upon receiving the trigger signal from the event trigger 35, the system being powered on for the first time, or reaching the preset start-up time, the temperature control valve 32 is opened to the minimum opening degree and the heating process is started.

[0048] When the system is first powered on, reaches the preset power-on time (e.g., 7:00 AM daily), or when the event trigger 35 detects a user approaching or using water, a usage trigger signal is generated. After receiving the trigger signal, the main controller 33 opens the temperature control valve 32 to its minimum opening, starts the heating control process and begins timing, allowing hot return water to flow through the sink heating circuit 22 to initially heat the countertop for a duration of τ1.

[0049] S2. Based on the real-time temperature collected by the temperature sensor 31, adjust the opening of the temperature control valve 32 to maintain the temperature of the washbasin body 21 within the preset evaporation target temperature range.

[0050] Temperature sensor 31 collects the temperature T1 of the washbasin body 21 in real time and transmits the signal to the main controller 33 through signal line 34.

[0051] The main controller 33 compares the collected temperature T1 with the preset safe upper temperature limit T2 = 45℃. If T1 > 45℃, it controls the temperature control valve 32 to reduce the opening (e.g., reduce by 10%) or close it directly, reducing or interrupting the hot water return flow. After a waiting delay τ1 = 1 minute, the temperature is collected again, and the cycle is cyclically adjusted until T1 ≤ 45℃.

[0052] The main controller 33 compares the collected temperature T1 with the preset lower limit T3 = 35℃. If T1 < 35℃, it controls the temperature control valve 32 to increase the opening (e.g., by 10%), thereby increasing the flow rate of the hot water return. After a delay of τ2, the temperature is collected again, and the cycle is repeated until T1 ≥ 35℃.

[0053] If T1 is between 35℃ and 45℃, the current opening of the temperature control valve 32 remains unchanged. The timing unit resets and starts timing again. After a delay of τ3, the temperature is re-acquired, forming a periodic temperature feedback closed-loop regulation process to stabilize the table surface temperature within the target evaporation range. Temperature hysteresis control avoids frequent valve operation, extending the equipment's lifespan.

[0054] S3. When the water stain detection device 36 detects that the table surface has reached a preset dry state, the heating duration has reached a preset upper limit, or the preset shutdown time has been reached, the temperature control valve 32 is closed or reduced to the minimum opening and the heating process is ended.

[0055] During the closed-loop regulation process, the main controller 33 continuously receives signals from the water stain detection device 36. When both the capacitive water film sensor and the image acquisition unit determine that the table surface has reached the preset dry state, the heating duration has reached the preset upper limit, or the preset shutdown time (such as 22:00 every day), the main controller 33 controls the temperature control valve 32 to close, ending the current heating control process, and the system enters standby mode.

[0056] In this embodiment, the building's centralized hot water return main pipe 11 is made of PPR pipe with a nominal diameter of DN25 and an inner diameter of D. m The washbasin heating circuit 22 is approximately 20mm thick. It uses copper tubing with a cross-section of a×b=10mm×5mm. Therefore, its equivalent hydraulic diameter is: The washbasin heating circuit 22 is connected to the building's central hot water return main 11 via two normally open hot water return branches 12, with a distance Δl = 0.5m between the two normally open hot water return branches 12. The washbasin heating circuit 22 is arranged in a serpentine pattern and embedded within the heat conduction channel 23 of the washbasin body 21. The spacing between the heating circuits 22 is 50mm, and the distance from the side wall or the opening of the washbasin is 25mm. Therefore, in this example, the total length of the heating circuit 22 is Ls ≈ 18m.

[0057] When the heating system is working normally, the flow rate through the return water main pipe 11 is: The flow rate through the handwashing sink heating circuit 22 is In this embodiment, take Furthermore, the local resistance is estimated at 30% of the friction loss. According to the Hayzen-Williams formula, the head loss along the flow direction of the return water main 11 is: The head loss along the water flow direction of the sink heating circuit 22 is: In the formula, and The Hayzen-Williams coefficient, , Intra-loop pressure closure difference The corrected flow rate within the loop is: The maximum permissible intra-loop pressure closure difference in this embodiment Take the initial flow rate through the return water main pipe 11. The initial flow rate through the handwashing sink heating circuit 22 After iterative adjustment, the actual flow rate value is obtained. , .

[0058] The flow rate of the washbasin heating circuit 22 is 12.7% of the flow rate of the building's centralized hot water return main pipe 11. That is, without the installation of an independent booster device, the flow rate of hot water flowing through the washbasin heating circuit 22 is hydraulically self-limited under the pressure difference of the centralized hot water return system. This utilizes the waste heat of the hot water return system while avoiding significant impact on the hydraulic balance of the original centralized hot water return system.

[0059] Table 1. Calculation of Pipeline Network Adjustment

Claims

1. A smart temperature-controlled evaporation system for a handwashing station based on waste heat from centralized hot water return, characterized in that, include: The handwashing basin heating circuit (22) is located inside the handwashing basin body (21), and its input and output ends are connected to the hot return water main pipe (11) of the building's centralized hot water supply system via the hot return water branch (12); The temperature control system (3) includes at least one temperature sensor (31) for detecting the temperature of the washbasin body (21), an adjustable opening temperature control valve (32) disposed on the hot water return branch (12), at least one event trigger (35) for generating a trigger signal when the washbasin is used or the surface is wet, at least one water stain detection device (36) for detecting the wet surface of the washbasin, and a main controller (33) that is connected to the temperature sensor (31), the temperature control valve (32), and the event trigger (35) respectively. The main controller (33) is configured as follows: Upon receiving the trigger signal from the event trigger (35), the system being powered on for the first time, or the preset start-up time, the temperature control valve (32) is opened to the minimum opening degree and the heating process is started; Based on the real-time temperature collected by the temperature sensor (31), the opening of the temperature control valve (32) is adjusted so that the temperature of the washbasin body (21) is maintained within the preset evaporation target temperature range; When the water stain detection device (36) detects that the table surface has reached a preset dry state, the heating duration has reached a preset upper limit, or the preset shutdown time has been reached, the temperature control valve (32) is closed or reduced to the minimum opening and the heating process is ended.

2. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The cross-section of the handwashing basin heating circuit (22) is smaller than that of the hot water return main pipe (11), so that the flow rate of hot water flowing through the handwashing basin heating circuit (22) is hydraulically self-limited under the pressure difference of the centralized hot water return system.

3. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The washbasin body (21) is provided with a heat conduction channel (23), and the washbasin heating circuit (22) is embedded in the heat conduction channel (23) and forms an integral heat exchange structure with the washbasin body (21).

4. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The handwashing basin heating circuit (22) is a serpentine, ring or multi-circuit structure to increase the contact area with the handwashing basin body (21).

5. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The heating circuit (22) of the washbasin is provided with an insulation layer (24) on the side away from the washbasin body (21).

6. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The temperature control valve (32) is a fail-close valve. When the main controller (33) is abnormal, the power supply is interrupted, or the control signal is lost, the hot water return branch (12) will be automatically closed.

7. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The water stain detection device (36) includes an image acquisition unit and an image processing unit. The image acquisition unit acquires images of the washbasin countertop, and the image processing unit analyzes the images of the washbasin countertop to identify water stain distribution, reflection characteristics, or wet areas on the surface, and determines whether the washbasin countertop is in a dry state.

8. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized hot water return waste heat according to claim 1, characterized in that, The water stain detection device (36) includes a humidity sensor, a capacitive water film sensor, a resistive water stain sensor or a conductive water film detection unit, used to detect changes in humidity on or near the surface of the washbasin.

9. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 1, characterized in that, The event trigger (35) can generate the use trigger signal based on water usage behavior, human and operational perception, or feedback signals from the water stain detection device.

10. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized hot water return waste heat according to claim 9, characterized in that, When the event trigger (35) generates the use trigger signal based on water usage behavior, including a flow sensor or water flow switch installed on the water inlet pipe of the sink, the use trigger signal is generated when water flow is detected in the water inlet pipe of the sink.

11. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized heat return water waste heat according to claim 9, characterized in that, When the event trigger (35) generates the use trigger signal based on human body and operation perception, including but not limited to at least one of infrared sensor, millimeter-wave radar sensor, pressure sensor, photoelectric sensor or touch switch, it is used to detect the user's behavior of approaching, touching or operating the handwashing station and generate the use trigger signal.

12. The intelligent temperature-controlled evaporation system for handwashing basins based on centralized hot water return waste heat according to claim 9, characterized in that, The event trigger (35) responds to the feedback signal of the water stain detection device (36) and generates the use trigger signal when the water stain detection device detects that the washbasin countertop is wet.

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