Villa domestic hot water system with zero cold water outlet

Abstract

The utility model relates to a villa domestic hot water system with zero cold water outlet, and belongs to the field of building water supply and drainage. Comprising a hot water supply pipe for conveying hot water to each water consumption point; the temperature probe is installed on the hot water supply pipe and used for detecting the water temperature in the hot water supply pipe and transmitting a temperature signal; the controller is connected with the temperature probe and used for receiving the temperature signal and controlling starting and stopping of the self-control heat tracing cable belt according to the set temperature; the self-control heat tracing cable belt is tightly laid on the outer side of the hot water supply pipe, is connected with the controller and is used for heating the hot water supply pipe, compensating heat loss and maintaining the water temperature in the pipeline under the control of the controller; and the power supply wiring switch is connected with the controller and the self-control heat tracing cable belt and is used for controlling the power supply of the whole system. A traditional circulating pipeline and a circulating pump are omitted, so that the length of the pipeline is shortened, the occupied area and initial investment of the system are reduced, and the overhaul and maintenance workload of equipment is reduced.

Description

Technical Field

[0001] This utility model relates to the field of building water supply and drainage technology, and in particular to a villa domestic hot water system with zero cold water output. Background Technology

[0002] The goals of carbon peaking and carbon neutrality place higher demands on carbon emission reduction across all industries. my country's energy structure will also undergo significant adjustments in the future, making carbon emission reduction in conventional industries a crucial research direction. Traditional domestic hot water systems employ hot water circulation pipes and pumps to maintain the temperature of hot water from sanitary fixtures, keeping the hot water circulating within these pipes. This circulation and repeated heating of the hot water within the pipes results in substantial energy waste. This invention eliminates the hot water circulation pipes and pumps, significantly reducing energy consumption and thus carbon emissions compared to traditional methods. Therefore, it represents an effective technological route for achieving carbon peaking and carbon neutrality goals. Utility Model Content

[0003] The purpose of this invention is to provide a villa domestic hot water system with zero cold water output, thereby solving the aforementioned problems existing in the prior art.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A villa domestic hot water system with zero cold water output includes:

[0006] Hot water supply pipes are used to deliver hot water to various water usage points;

[0007] A temperature probe is installed on the hot water supply pipe to detect the water temperature inside the pipe and transmit the temperature signal.

[0008] The controller, connected to the temperature probe, is used to receive temperature signals and control the start and stop of the self-controlled heating cable belt according to the set temperature.

[0009] The self-controlled heating cable is laid close to the outside of the hot water supply pipe and connected to the controller. It is used to heat the hot water supply pipe under the control of the controller, compensate for heat loss, and maintain the water temperature in the pipe.

[0010] The power supply wiring switch, connected to the controller and the automatic heat tracing cable, is used to control the power supply of the entire system.

[0011] In some specific embodiments, the temperature probe is installed on the hot water supply pipe near the water appliance end and on the longer part of the pipeline, and is connected to the outer wall of the hot water supply pipe by a fixing device and connected to the controller by a signal line.

[0012] In some specific embodiments, the controller is installed in the equipment room or electrical control box, connected to the signal line of the temperature probe through the signal receiving port, and connected to the self-controlled heat tracing cable through the control output port.

[0013] In some specific embodiments, the self-controlled heat tracing cable is laid along the entire route of the hot water supply pipe, covering the main pipe and branch pipes of the hot water supply pipe. It is fixed to the outer wall of the hot water supply pipe by special fasteners. One end of the cable is connected to the control output port of the controller, and the other end is connected to the power supply system. The power supply line is controlled by the power supply wiring switch.

[0014] In some specific embodiments, the power supply wiring switch is installed in the equipment room or distribution box and connected to the power supply line of the controller and the power supply line of the self-controlled heat tracing cable.

[0015] In some specific embodiments, the temperature probes are installed at intervals of 5-10 meters, and temperature probes are installed at pipe branches and in front of water appliances.

[0016] In some specific embodiments, the power range of the self-controlled heating cable is 10-30W / m, and its surface is provided with a high-temperature resistant insulation layer.

[0017] In some specific embodiments, the hot water supply pipe is also provided with an insulation layer, and the temperature probe and the self-controlled heat tracing cable are installed on the outside of the insulation layer.

[0018] The beneficial effects of this utility model are as follows: This utility model discloses a villa domestic hot water system with zero cold water output, including a hot water supply pipe for delivering hot water to each water point; a temperature probe installed on the hot water supply pipe for detecting the water temperature inside the pipe and transmitting the temperature signal; a controller connected to the temperature probe for receiving the temperature signal and controlling the start and stop of the self-controlled heating cable strip according to the set temperature; the self-controlled heating cable strip, laid close to the outside of the hot water supply pipe and connected to the controller, for heating the hot water supply pipe under the control of the controller to compensate for heat loss and maintain the water temperature inside the pipe; and a power supply switch connected to the controller and the self-controlled heating cable strip for controlling the power supply of the entire system. This utility model eliminates the circulation pipes and circulation pumps of traditional domestic hot water systems, achieving the shortest hot water system pipeline, halving the pipe length, reducing the area occupied by the system, lowering the initial investment in the system pipelines, and reducing the maintenance work of circulation pipes, circulation pumps, and other equipment. Because the system ensures the water temperature in the hot water pipes, water resources will not be wasted due to long waiting times for hot water. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a villa domestic hot water system with zero cold water output according to this utility model.

[0020] In the attached diagram: 1. Hot water supply pipe; 2. Temperature probe; 3. Controller; 4. Self-controlled heat tracing cable; 5. Power supply wiring switch. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0022] Reference Figure 1 The villa domestic hot water system with zero cold water output shown is characterized by comprising:

[0023] Hot water supply pipe (1) is used to transport hot water to various water points;

[0024] Temperature probe (2) is installed on hot water supply pipe (1) to detect the water temperature in hot water supply pipe (1) and transmit the temperature signal;

[0025] The controller (3) is connected to the temperature probe (2) to receive temperature signals and control the start and stop of the self-controlled heating cable (4) according to the set temperature.

[0026] It is necessary to explain in detail here that the self-controlled heating cable (4) can be connected to the controller (3) through electrical wiring: Specifically:

[0027] A multi-core cable is led out from the control output port of the controller (3), and each core wire corresponds to the transmission of a specific control signal of a self-controlled heat tracing cable (4) or a self-controlled heat tracing cable (4).

[0028] One end of the self-controlled heat tracing cable (4) is equipped with a matching terminal block. The core wire of the multi-core cable is connected to the terminal block, and the core wire is connected to the control circuit inside the self-controlled heat tracing cable (4) through fastening bolts and other connecting parts, thereby realizing the transmission of control signals from the controller (3) to the self-controlled heat tracing cable (4).

[0029] When the controller (3) determines that the self-controlled heat tracing cable tape (4) needs to be activated based on the temperature signal transmitted by the temperature probe (2), the control circuit inside the controller (3) is turned on, and a start signal is sent to the terminal of the self-controlled heat tracing cable tape (4) through the multi-core cable. This signal is usually a level signal with a certain voltage and current. After receiving the signal, the control circuit inside the self-controlled heat tracing cable tape (4) triggers the heat tracing tape to start working and heat the hot water supply pipe (1).

[0030] Meanwhile, the working status feedback signal of the self-controlled heat tracing cable (4) will also be transmitted back to the controller (3) through the terminal block and multi-core cable. The controller (3) monitors the working status of the self-controlled heat tracing cable (4) according to the feedback signal to ensure its normal operation.

[0031] The self-controlled heating cable (4) is laid close to the outside of the hot water supply pipe (1) and connected to the controller (3). It is used to heat the hot water supply pipe (1) under the control of the controller (3), to compensate for heat loss and maintain the water temperature in the pipe.

[0032] The power supply wiring switch (5) is connected to the controller (3) and the self-controlled heating cable (4) to control the power supply of the entire system.

[0033] The specific connection method is as follows:

[0034] 1. Connection between power supply wiring switch (5) and controller (3)

[0035] Power supply cable

[0036] A power line, typically consisting of two wires (live and neutral, for AC power systems), is drawn from the building's main power supply line (such as the distribution box of a villa). The live and neutral wires of this power line are connected to the input terminals of the power supply wiring switch (5).

[0037] The output terminal of the power supply switch (5) is connected to the power input terminal of the controller (3) through another power line (live wire and neutral wire). When the power supply switch (5) is closed, current flows to the controller (3) to provide operating power to the controller (3).

[0038] II. Connection between power supply wiring switch (5) and self-controlled heating cable (4)

[0039] Power cord connection

[0040] The self-regulating heat tracing cable (4) requires electricity to generate heat. Another power line (live and neutral wires) is led out from the output terminal of the power supply switch (5) and connected to the power input terminal of the self-regulating heat tracing cable (4). This connection is usually made through a terminal block, and the power input terminal of the self-regulating heat tracing cable (4) is designed with a dedicated wiring interface.

[0041] When the power supply connection switch (5) is closed, the current flows through the power line to the self-controlled heat tracing cable (4), causing it to start heating and providing heat tracing function for the hot water supply pipe (1).

[0042] This connection method enables the power supply switch (5) to centrally control the power supply of the entire system. The power supply of the system can be turned on and off through simple switch operation, ensuring the safe operation of the system.

[0043] In some specific embodiments, the temperature probe (2) is installed on the hot water supply pipe (1) near the water appliance end and the longer part of the pipeline, and is connected to the outer wall of the hot water supply pipe (1) by a fixing device and connected to the controller (3) by a signal line.

[0044] In some specific embodiments, the controller (3) is installed in the equipment room or electrical control box, connected to the signal line of the temperature probe (2) through the signal receiving port, and connected to the self-controlled heat tracing cable (4) through the control output port.

[0045] In some specific embodiments, the self-controlled heat tracing cable (4) is laid along the entire route of the hot water supply pipe (1), covering the main pipe and branch pipes of the hot water supply pipe (1), and is fixed to the outer wall of the hot water supply pipe (1) by special fasteners. One end of the cable is connected to the control output port of the controller (3), and the other end is connected to the power supply system. The power supply line is controlled to be switched on and off by the power supply connection switch (5).

[0046] In some specific embodiments, the power supply wiring switch (5) is installed in the equipment room or distribution box and connected to the power supply line of the controller (3) and the power supply line of the self-controlled heat tracing cable (4).

[0047] In some specific embodiments, the temperature probes (2) are installed at intervals of 5-10 meters, and temperature probes 2 are installed at pipe branches and in front of water appliances.

[0048] In some specific embodiments, the power range of the self-controlled heating cable 4 is 10-30W / m, and its surface is provided with a high-temperature resistant insulation layer.

[0049] In some specific embodiments, the hot water supply pipe 1 is also provided with an insulation layer, and the temperature probe 2 and the self-controlled heat tracing cable 4 are both installed on the outside of the insulation layer.

[0050] The controller 3 has a delay control function. When the temperature detected by the temperature probe 2 is lower than the start-up set temperature, the controller 3 will delay for 5-10 minutes before starting the self-controlled heat tracing cable 4. The addition of the delay control function can avoid frequent start-stop of the heat tracing cable due to short-term temperature fluctuations, reduce the wear and tear on the equipment caused by frequent start-stop, and also help stabilize the temperature in the hot water supply pipe.

[0051] The power supply switch 5 has an emergency disconnect function, and the system can only be restarted by manual reset after an emergency disconnect. The emergency disconnect function can quickly cut off the power supply in case of system failure or emergency, ensuring user safety; the manual reset can prevent the system from automatically restarting before the fault is eliminated, further improving system safety.

[0052] The working principle and steps of this system:

[0053] Working principle

[0054] The working principle of this villa domestic hot water system is mainly based on real-time temperature monitoring and precise temperature control of the hot water supply pipe. Through the coordinated operation of temperature probes, controllers, and self-regulating heat tracing cables, the system maintains the water temperature in the hot water supply pipe, achieving zero cold water output while reducing energy consumption and carbon emissions.

[0055] The temperature probe monitors the water temperature in the hot water supply pipe in real time and transmits the temperature signal to the controller. The controller compares the set temperature value with the actual water temperature and controls the start and stop of the self-controlled heating cable belt to compensate for the heat loss of the hot water supply pipe.

[0056] Work steps

[0057] System initialization: The power supply switch is closed, and the entire system is powered on.

[0058] The controller performs a self-test upon power-on, and the temperature probe begins real-time monitoring of the water temperature in the hot water supply pipe.

[0059] Temperature monitoring and signal transmission: Temperature probes are installed at key locations on the hot water supply pipe, such as near the water appliance or in long sections of the pipe.

[0060] The temperature probe monitors the water temperature in the hot water supply pipe in real time and transmits the temperature signal to the controller via a signal line.

[0061] Controller judgment and control command issuance: The controller is preset with a start temperature usually set to 45℃ and a stop temperature usually set to the start temperature + 2℃.

[0062] When the temperature signal received by the controller is lower than the start-up temperature, the controller issues a start-up command and sends a start-up signal to the self-controlled heat tracing cable through the control output port.

[0063] When the temperature signal received by the controller reaches or exceeds the stop temperature, the controller issues a stop command and cuts off the power supply circuit of the self-controlled heating cable.

[0064] Self-controlled heat tracing cable working: The self-controlled heat tracing cable is laid close to the outside of the hot water supply pipe.

[0065] When the self-controlled heating cable receives the start signal from the controller, it begins to be powered on and heats up the hot water supply pipe to compensate for the heat loss of the hot water supply pipe, so that the water temperature in the pipe gradually increases.

[0066] When the self-controlled heating cable receives a stop signal from the controller, it stops heating.

[0067] Special operating condition handling: If the water temperature in the hot water supply pipe does not reach the stop temperature within 20 minutes after the automatic heating cable is started, the controller will determine that it is a special operating condition, such as excessive hot water consumption leading to insufficient water supply capacity of the water heater.

[0068] The automatic protection mechanism cuts off the power supply circuit of the self-controlled heating cable, stopping the heating process.

[0069] After 20 minutes, the controller automatically restored the initial settings and restarted the process of monitoring and controlling the temperature of the hot water supply pipe.

[0070] Based on the above working principles and steps, this villa domestic hot water system with zero cold water output can provide hot water instantly, avoiding water waste caused by waiting for hot water, while significantly reducing energy consumption and carbon emissions, and has good energy-saving effect and practical application value.

[0071] Example

[0072] This embodiment uses a villa with a building area of ​​140㎡ as an application scenario to introduce in detail a villa domestic hot water system with zero cold water output and its working process.

[0073] I. System Composition and Installation

[0074] Hot water supply pipe installation

[0075] Copper pipes are used for the hot water supply, with the pipe diameter determined based on the number and distribution of hot water appliances within the villa. The pipes originate from the gas water heater outlet and are laid along pre-embedded grooves in the villa's walls and floors, branching out to various water appliances such as bathroom showerheads, kitchen faucets, and laundry room faucets. Special copper pipe fittings are used for pipe connections to ensure sealing and pressure resistance.

[0076] Temperature probe arrangement

[0077] Multiple temperature probes are installed near each water appliance on the hot water supply pipe, such as in front of the shower head in the bathroom, the faucet in the kitchen, and in longer sections of the pipe, such as the main pipe from the water heater to the second-floor bathroom. The temperature probes are fixed to the outer wall of the hot water supply pipe with pipe clamps, and their sensing ends are tightly attached to the pipe wall. The signal wires are led to the controller installation location through pre-buried pipes along the wall.

[0078] Controller installation

[0079] The controller is a programmable controller with multi-channel temperature signal acquisition and multi-channel relay output control functions, installed in the villa's equipment room. The controller is fixed to the wall with bolts, its power input is connected to the villa's electrical distribution box, its temperature signal input is connected to the temperature probe signal line, and its relay output is connected to the self-controlled heat tracing cable via a control cable.

[0080] Self-controlled heat tracing cable laying

[0081] A 20W / m self-regulating heat tracing cable is selected and laid tightly against the outside of the hot water supply pipe. It is laid along the entire length of the hot water supply pipe, covering both the main pipe and branch pipes. The self-regulating heat tracing cable is secured to the outer wall of the hot water supply pipe using special fasteners such as plastic cable ties, with a fixing point every 30cm to ensure a tight fit between the cable and the pipe. One end of the heat tracing cable is led to the controller installation location and connected to the controller relay output terminal; the other end is connected to the power supply system and controlled by a power supply switch.

[0082] Power supply wiring switch installation

[0083] The power supply wiring switch is a double-pole circuit breaker with overload protection and emergency disconnection functions, installed in the distribution box in the equipment room. Its input terminal is connected to the main power supply line of the villa, and its output terminal is divided into two paths: one path is connected to the power input terminal of the controller, and the other path is connected to the power supply line of the automatic heat tracing cable.

[0084] II. System Working Process

[0085] System Initialization

[0086] With the power supply switch closed, the entire system is powered on. The controller performs a power-on self-test, all indicator lights illuminate normally, and the temperature probe begins real-time monitoring of the water temperature in the hot water supply pipe.

[0087] Normal working status

[0088] When the water temperature in the hot water supply pipe drops below the set starting temperature of 45℃ due to heat loss, especially if no one uses the hot water at night, the water temperature in the pipe gradually decreases. The temperature probe monitors the temperature change in real time and transmits the temperature signal below 45℃ to the controller.

[0089] After receiving the temperature signal, the controller compares it with the set temperature and determines that heat tracing needs to be activated. The controller relay output is activated, sending a start signal to the automatic heat tracing cable. The automatic heat tracing cable is then energized and heats up, tracing the hot water supply pipe.

[0090] As the self-controlled heating cable belt heats up, the water temperature in the hot water supply pipe gradually increases. When the water temperature reaches the set stop temperature of 47℃, the temperature probe transmits the temperature signal to the controller. The controller determines that the stop temperature has been reached, and the relay output cuts off the power supply circuit of the self-controlled heating cable belt, stopping the heating.

[0091] Operating status when water is used

[0092] When a user turns on a water appliance to use hot water, such as turning on the shower in the morning, hot water flows from the water heater and is delivered to the showerhead through the hot water supply pipe. Because the self-regulating heat tracing cable maintains the water temperature in the hot water supply pipe, the user does not need to wait too long for the cold water to run out before obtaining hot water at a suitable temperature, reducing water waste.

[0093] Special working condition handling

[0094] In cold weather, if a large gathering is held in the villa and hot water is used frequently, the water heater's supply capacity may be insufficient, causing the water temperature in the hot water supply pipe to fail to reach 47°C within 20 minutes after the self-regulating heating cable is activated. The controller will recognize this as a special operating condition and automatically trigger the protection mechanism, cutting off the power supply circuit to the self-regulating heating cable and stopping heating to prevent excessive energy consumption due to prolonged heating.

[0095] After 20 minutes, the controller automatically restored its initial settings and re-monitored the temperature of the hot water supply pipe. Once the water heater's supply capacity was restored, the water temperature in the hot water supply pipe gradually returned to the normal range under the action of the heating cable, and the system continued to operate normally.

[0096] III. System Effectiveness Evaluation

[0097] Energy saving effect

[0098] Compared to traditional mechanical circulation systems, this system eliminates hot water circulation pipes and pumps, reducing pipe length and equipment energy consumption. Water resources are saved.

[0099] By achieving zero cold water output, the waste of cold water while users wait for hot water is avoided. Carbon emissions are reduced.

[0100] By adopting the above-disclosed technical solution of this utility model, the following beneficial effects are obtained:

[0101] Significant energy-saving effect

[0102] This system effectively reduces energy consumption by eliminating traditional hot water circulation pipes and pumps. Taking a villa residential system as an example, under winter operating conditions in Beijing, compared with a mechanical circulation system, the main energy consumption of the self-regulating electric heat tracing system is the electricity consumed for pipe heat tracing, while the main energy consumption of the mechanical circulation system is the gas consumption for heating water in the pipes by the water heater and the electricity consumption of the hot water circulation pump.

[0103] Significant water-saving effect

[0104] The system achieves zero cold water output for domestic hot water, avoiding the waste of cold water while waiting for hot water. In traditional hot water systems, users need to wait for a period of time after turning on the water appliance to obtain hot water, and the cold water flowing out during this time is often wasted.

[0105] Reduce carbon emissions

[0106] Because the system significantly reduces energy consumption, it correspondingly reduces carbon emissions. In traditional hot water systems, the use of gas water heaters generates large amounts of greenhouse gases such as carbon dioxide.

[0107] Improve user comfort

[0108] This system provides users with a more convenient and comfortable hot water experience. Users no longer need to wait for the cold water to run out before receiving hot water at a suitable temperature, reducing waiting time and improving comfort. Whether it's washing up in the morning or taking a shower in the evening, users can quickly enjoy hot water, enhancing convenience and comfort.

[0109] Reduce system footprint and initial investment

[0110] Compared to traditional hot water systems, this system eliminates the hot water circulation pipes and pumps, simplifying the system structure. This not only reduces the system's footprint but also lowers initial investment costs. In villa buildings, space resources are typically limited, and the system's streamlined design better adapts to the layout characteristics of villas, saving space. Furthermore, the simplified system reduces equipment procurement and installation costs, lowering the initial investment burden for users.

[0111] Reduce equipment maintenance costs

[0112] Traditional hot water systems require regular inspection and maintenance of their hot water circulation pipes and pumps to ensure normal operation. This system eliminates these components, thus reducing the workload and costs associated with inspection and maintenance. The self-regulating heat tracing cable has a long service life and high reliability, requiring only simple checks and maintenance to keep it functioning properly, further reducing system operating and maintenance costs.

[0113] Extend the lifespan of your water heater

[0114] In traditional hot water systems, water heaters need to frequently heat the water in the pipes to maintain the water temperature. However, this system's self-regulating heat tracing cable maintains the water temperature in the supply pipes, reducing the number of times the water heater needs to be started. This helps extend the water heater's lifespan, reduce its failure rate, and lower equipment replacement costs.

[0115] Wide range of applications

[0116] This system is suitable for all types of villas, whether newly built or renovated, and can be easily installed and applied. Its flexible system design can adapt to different villa layouts and hot water needs, giving it wide applicability and promising market prospects.

[0117] In summary, the villa domestic hot water system with zero cold water output provided by this utility model has significant energy-saving and water-saving effects, can reduce carbon emissions, improve user comfort, reduce system footprint and initial investment, reduce equipment maintenance costs, extend the service life of water heaters, and has a wide range of applications and good market application prospects.

[0118] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A villa domestic hot water system with zero cold water outlet, characterized in that, include: Hot water supply pipe (1) is used to transport hot water to various water points; Temperature probe (2) is installed on the hot water supply pipe (1) to detect the water temperature in the hot water supply pipe (1) and transmit the temperature signal; The controller (3) is connected to the temperature probe (2) and is used to receive temperature signals and control the start and stop of the self-controlled heating cable (4) according to the set temperature. The self-controlled heating cable (4) is laid close to the outside of the hot water supply pipe (1) and connected to the controller (3). It is used to heat the hot water supply pipe (1) under the control of the controller (3), compensate for heat loss, and maintain the water temperature in the pipe. The power supply wiring switch (5) is connected to the controller (3) and the self-controlled heat tracing cable (4) and is used to control the power supply of the entire system.

2. The villa domestic hot water system with zero cold water outlet according to claim 1, characterized in that, The temperature probe (2) is installed on the hot water supply pipe (1) near the water appliance and on the longer part of the pipe. It is connected to the outer wall of the hot water supply pipe (1) by a fixing device and connected to the controller (3) by a signal line.

3. The villa domestic hot water system with zero cold water outlet according to claim 1, characterized in that, The controller (3) is installed in the equipment room or electrical control box, and is connected to the signal line of the temperature probe (2) through the signal receiving port, and connected to the self-controlled heat tracing cable (4) through the control output port.

4. The villa domestic hot water system with zero cold water outlet according to claim 1, characterized in that, The self-controlled heat tracing cable (4) is laid along the entire route of the hot water supply pipe (1), covering the main pipe and branch pipes of the hot water supply pipe (1). It is fixed to the outer wall of the hot water supply pipe (1) by special fasteners. One end of the cable is connected to the control output port of the controller (3), and the other end is connected to the power supply system. The power supply line is controlled to open and close by the power supply connection switch (5).

5. The villa domestic hot water system with zero cold water outlet according to claim 1, characterized in that, The power supply wiring switch (5) is installed in the equipment room or distribution box and is connected to the power supply line of the controller (3) and the power supply line of the self-controlled heat tracing cable (4).

6. The villa domestic hot water system with zero cold water output according to claim 1, characterized in that, The temperature probes (2) are installed at intervals of 5-10 meters, and temperature probes (2) are installed at pipe branches and in front of water appliances.

7. The villa domestic hot water system with zero cold water output according to claim 1, characterized in that, The power range of the self-controlled heat tracing cable (4) is 10-30W / m, and its surface is provided with a high-temperature resistant insulation layer.

8. The villa domestic hot water system with zero cold water output according to claim 1, characterized in that, The hot water supply pipe (1) is also provided with an insulation layer, and the temperature probe (2) and the self-controlled heat tracing cable (4) are both installed on the outside of the insulation layer.

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