A hot water preheating system

Abstract

This utility model discloses a hot water preheating system, which includes a water heater, a four-way reversing valve, a bypass pipe, a heating pipe, and at least two water points. The water heater includes a cold water pipe and a hot water pipe. The cold water pipe is used to input cold water, and the hot water pipe is used to output hot water. The inlet of the four-way reversing valve is connected to the hot water pipe, and the four-way reversing valve is communicatively connected to the water heater. The inlet of the bypass pipe is connected to the bypass port, and the outlet of the bypass pipe is connected to the cold water pipe. The first end of the heating pipe is connected to the first reversing port, and the second end of the heating pipe is connected to the second reversing port. The water points are connected to the heating pipe and the cold water pipe, respectively. Before each preheating, the shortest heating pipe length is selected, and a corresponding circulating preheating hot water path is formed through the reversing action of the four-way reversing valve. Then, preheating is performed. Applying the above-mentioned hot water preheating system helps to shorten the preheating time of water points at more distant locations, reduce heat loss in the pipeline during the preheating process, and improve the user experience.

Description

Technical Field

[0001] This utility model relates to hot water preheating technology, and more particularly to a hot water preheating system. Background Technology

[0002] Preheating function refers to the technology of water heaters that provide hot water instantly without requiring users to wait for cold water to flow out. This technology uses a circulation pump inside the water heater to circulate and preheat the water before the user uses it. Cold water is circulated back to the water heater for preheating, ensuring that the pipes are full of hot water, thus avoiding the need to wait for cold water to be discharged from the point of use.

[0003] Traditional hot water preheating systems typically connect a return pipe between the hot water pipe at the furthest point of use and the water inlet of the water heater. During preheating, cooled water from the hot water pipe flows back to the water heater through the return pipe, is reheated, and then re-enters the hot water pipe. Alternatively, a one-way valve is installed between the hot water pipe and the cold water pipe at the furthest point of use. During preheating, cooled water from the hot water pipe flows back to the water heater through the one-way valve and the cold water pipe, is reheated, and then re-enters the hot water pipe. This type of hot water preheating system results in the entire system's piping (hot water pipe and return pipe; or hot water pipe and cold water pipe) being filled with hot water when a point of use requires hot water and the preheating function is activated, leading to increased energy consumption of the water heater. To solve this problem, current methods control the preheating time based on the length of the hot water pipe between the point of use and the water heater, stopping preheating when hot water arrives at the point of use.

[0004] However, when water is used at a relatively far point, the pipe length between the water point and the water heater is relatively long, and preheating still takes a long time. In addition, there is the problem of heat loss in the pipe, which results in the hot water temperature reaching the water point not meeting the user's needs, thus reducing the user experience. Utility Model Content

[0005] One of the technical problems solved by this utility model is to provide a hot water preheating system that helps to shorten the preheating time at the point of use, reduce heat loss in the pipeline during the preheating process, and improve the user experience.

[0006] The above-mentioned technical problems are solved by the following technical solutions:

[0007] A hot water preheating system, comprising:

[0008] A water heater, comprising a cold water pipe and a hot water pipe, wherein the cold water pipe is used to input cold water and the hot water pipe is used to output hot water;

[0009] The four-way reversing valve includes an inlet D, a bypass port S, a first switching port E, and a second switching port C. The inlet D of the four-way reversing valve is connected to the hot water pipe, and the four-way reversing valve is communicatively connected to the water heater.

[0010] A bypass pipe, wherein the inlet of the bypass pipe is connected to the bypass port S, and the outlet of the bypass pipe is connected to the cold water pipe;

[0011] A heating pipe, wherein a first end of the heating pipe is connected to the first exchange port E, and a second end of the heating pipe is connected to the second exchange port C;

[0012] There are at least two water supply points, with the hot water inlet of each water supply point connected to the heating pipe and the cold water inlet of each water supply point connected to the cold water pipe.

[0013] The hot water preheating system provided by this utility model includes a water heater, a four-way reversing valve, a bypass pipe, a heating pipe, and at least two water usage points. The water heater includes a cold water pipe and a hot water pipe. The cold water pipe is used to input cold water, and the hot water pipe is used to output hot water. The four-way reversing valve includes an inlet, a bypass port, a first switching port, and a second switching port. The inlet of the four-way reversing valve is connected to the hot water pipe, and the four-way reversing valve is communicatively connected to the water heater. The inlet of the bypass pipe is connected to the bypass port, and the outlet of the bypass pipe is connected to the cold water pipe. The first end of the heating pipe is connected to the first switching port, and the second end of the heating pipe is connected to the second switching port. The system connects the hot water inlet of the water point to the heating pipe and the cold water inlet to the cold water pipe. Before each preheating cycle, the shortest heating pipe length is selected by comparing the lengths of the heating pipes between the current water point and the first and second exchange ports. This is achieved through the switching action of a four-way reversing valve, forming a corresponding circulating preheating hot water circuit. The preheated hot water then reaches the current water point through the shortest pipe. Applying this hot water preheating system helps to shorten the preheating time of the water point, reduce heat loss in the pipeline during the preheating process, and improve the user experience.

[0014] In some embodiments of this utility model, the four-way reversing valve and the bypass pipe are disposed inside the water heater;

[0015] The water heater is provided with an inlet L and two converters, namely a first converter M and a second converter N. The inlet L is connected to the cold water pipe. The first converter E is connected to the first converter M. The second converter C is connected to the second converter N. The first end of the heating pipe is connected to the first converter M. The second end of the heating pipe is connected to the second converter N.

[0016] In some embodiments of this utility model, the four-way reversing valve and the bypass pipe are disposed outside the water heater;

[0017] The water heater is provided with an inlet A and an outlet B. The inlet A is connected to the cold water pipe, and the outlet B is connected to the hot water pipe. The inlet D of the four-way reversing valve is connected to the outlet B.

[0018] In some embodiments of this utility model, a one-way valve is provided on the bypass pipe to allow water in the bypass pipe to flow unidirectionally from the bypass port S to the cold water pipe.

[0019] In some embodiments of this utility model, the hot water preheating system further includes at least two preheating signal triggers, each preheating signal trigger being associated with a corresponding water usage point and communicating with the water heater.

[0020] In some embodiments of this utility model, a temperature sensor is also provided at the connection point between the water point and the heating pipe, and the temperature sensor is communicatively connected to the water heater.

[0021] In some embodiments of this utility model, the water heater further includes a circulating water pump and a heating unit;

[0022] The inlet of the circulating water pump is connected to the cold water pipe, the outlet of the circulating water pump is connected to the inlet of the heating unit, and the outlet of the heating unit is connected to the hot water pipe.

[0023] In some embodiments of this utility model, the heating unit includes a burner and a heat exchanger;

[0024] The inlet of the heat exchanger is connected to the outlet of the circulating water pump, and the outlet of the heat exchanger is connected to the hot water pipe. The burner is used to ignite combustible gas to heat the heat exchanger.

[0025] In some embodiments of this utility model, the heating unit includes an inner liner and an electric heating element;

[0026] The inlet of the inner tank is connected to the outlet of the circulating water pump, and the outlet of the inner tank is connected to the hot water pipe. The inner tank is used to store hot water, and the electric heating tube is installed inside the inner tank to heat the water in the inner tank. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of a hot water preheating system provided by this utility model;

[0029] Figure 2 A schematic diagram of the liquid flow direction of the four-way reversing valve provided by this utility model in the first working state;

[0030] Figure 3 A schematic diagram of the liquid flow direction of the four-way reversing valve provided by this utility model in the second working state;

[0031] Figure 4 A schematic diagram of another hot water preheating system provided by this utility model;

[0032] Figure 5 A schematic flowchart of a preheating method provided by this utility model;

[0033] Figure 6 A flowchart of another preheating method provided by this utility model.

[0034] Explanation of reference numerals in the attached figures:

[0035] 110. Water heater; 111. Cold water pipe; 112. Hot water pipe; 113. Circulating water pump; 114. Heating unit; 120. Four-way reversing valve; 130. Bypass pipe; 131. One-way valve; 140. Heating pipe; 150. Water point; 151. Preheating signal trigger; 152. Temperature sensor.

[0036] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0037] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0038] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] In this utility model, the terms "first" and "second" are used only for descriptive purposes and have no special meaning.

[0040] Figure 1 This is a schematic diagram of the structure of a hot water preheating system provided by this utility model, as shown below. Figure 1 As shown, the hot water preheating system includes:

[0041] A water heater 110 includes a cold water pipe 111 and a hot water pipe 112. The cold water pipe 111 is used to input cold water, and the hot water pipe 112 is used to output hot water. The cold water pipe 111 is connected to an external water supply pipe to receive cold water from the external supply pipe. The input cold water is heated internally by the water heater 110 and then output through the hot water pipe 112. In this embodiment of the invention, the water heater 110 can be a gas water heater or an electric water heater; this embodiment is not limited thereto.

[0042] The four-way reversing valve 120 includes an inlet D, a bypass port S, a first switching port E, and a second switching port C. The inlet D of the four-way reversing valve 120 is connected to the hot water pipe 112, and the four-way reversing valve 120 is communicatively connected to the water heater 110. Figure 2 This is a schematic diagram of the liquid flow direction of the four-way reversing valve provided by this utility model in its first working state. Figure 3 This is a schematic diagram of the liquid flow direction of the four-way reversing valve 120 in the second working state provided by this utility model. The four-way reversing valve 120 can switch between the first and second working states under the control of the water heater 110. For example, Figure 2 As shown, in the first operating state, the inlet D of the four-way reversing valve 120 is connected to the first switching port E, and the bypass port S is connected to the second switching port C, as follows. Figure 3 As shown, in the second working state, the inlet D of the four-way reversing valve 120 is connected to the second reversing port C, and the bypass port S is connected to the first reversing port E.

[0043] Bypass pipe 130, the inlet of bypass pipe 130 is connected to bypass port S, and the outlet of bypass pipe 130 is connected to cold water pipe 111.

[0044] Heating pipe 140 (the pipe shown by the dashed line in the figure) has its first end connected to the first exchange port E and its second end connected to the second exchange port C.

[0045] There are at least two water points 150. The hot water inlet of water point 150 is connected to the heating pipe 140, and the cold water inlet of water point 150 is connected to the cold water pipe 111.

[0046] For example, the working principle of a hot water preheating system is as follows:

[0047] When the water heater 110 receives a preheating signal from the current water point, it acquires the length of the heating pipe 140 between the current water point and the first converter port E as the first pipe length PL1, and acquires the length of the heating pipe 140 between the current water point and the second converter port C as the second pipe length PL2. The current water point is one of at least two water points. The first pipe length PL1 and the second pipe length PL2 are compared. If the first pipe length PL1 is less than the second pipe length PL2, the four-way reversing valve 120 is controlled to operate in the first working state. Figure 1 , 2 As shown, in the first operating state, the inlet D of the four-way reversing valve 120 is connected to the first switching port E, and the bypass port S is connected to the second switching port C, forming a circulating preheating circuit from the first switching port E through the heating pipe 140, the second switching port C, the bypass port S, and the bypass pipe 130 back to the cold water pipe 111 of the water heater 110 in the first direction (counterclockwise direction in the figure). When the length of the second pipe PL2 is less than the length of the first pipe PL1, the four-way reversing valve 120 is controlled to operate in the second operating state, such as... Figure 1 , 3 As shown, in the second operating state, the inlet D of the four-way reversing valve 120 is connected to the second reversing port C, and the bypass port S is connected to the first reversing port E, forming a second-direction (clockwise direction in the figure) circulating preheating circuit from the second reversing port C through the heating pipe 140, the first reversing port E, the bypass port S, and the bypass pipe 130 back to the cold water pipe 111 of the water heater 110. Simultaneously with the operation of the four-way reversing valve 120, the water heater 110 responds to the preheating signal and performs a preheating operation, starting to heat water. During the preheating process, the preheating end signal is monitored in real time, and the preheating operation stops when the preheating end signal, which indicates that hot water has reached the current water usage point, is determined. For example, during the preheating process, the hot water temperature, preheating time, or circulating water flow rate of the current water point are monitored in real time. When the hot water temperature at the current water point reaches the preset range of the user's set temperature (e.g., set temperature ±3℃), the preheating time reaches the preset preheating time corresponding to the current water point, or the circulating water flow rate reaches the preset circulating flow rate corresponding to the current water point, it indicates that the hot water has arrived at the current water point, and the preheating operation is stopped at this time.

[0048] As can be seen from the above, before each preheating, by comparing the length of the heating pipe 140 between the water point and the first converter port E (first pipe length PL1) and the length of the heating pipe 140 between the water point and the second converter port C (second pipe length PL2), the shorter of the first pipe length PL1 and the second pipe length PL2 is determined. The four-way reversing valve 120 is then activated to form a corresponding circulating preheating hot water circuit. Preheating is then performed so that the preheated hot water reaches the current water point through the shortest pipe, reducing the preheating time for water points at more distant locations, reducing heat loss in the pipes during the preheating process, and improving the user experience.

[0049] It should be noted that, in order to avoid the situation where the first pipe length PL1 and the second pipe length PL2 are equal, the first pipe length PL1 and the second pipe length PL2 corresponding to each water point can be set to be unequal during the pipe laying and water point installation process.

[0050] The hot water preheating system provided by this utility model includes a water heater, a four-way reversing valve, a bypass pipe, a heating pipe, and at least two water usage points. The water heater includes a cold water pipe and a hot water pipe. The cold water pipe is used to input cold water, and the hot water pipe is used to output hot water. The four-way reversing valve includes an inlet, a bypass port, a first switching port, and a second switching port. The inlet of the four-way reversing valve is connected to the hot water pipe, and the four-way reversing valve is communicatively connected to the water heater. The inlet of the bypass pipe is connected to the bypass port, and the outlet of the bypass pipe is connected to the cold water pipe. The first end of the heating pipe is connected to the first switching port, and the second end of the heating pipe is connected to the second switching port. The system connects the hot water inlet of the water point to the heating pipe and the cold water inlet to the cold water pipe. Before each preheating cycle, the shortest heating pipe length is selected by comparing the lengths of the heating pipes between the current water point and the first and second exchange ports. This is achieved through the switching action of a four-way reversing valve, forming a corresponding circulating preheating hot water circuit. The preheated hot water then reaches the current water point through the shortest pipe. Applying this hot water preheating system helps to shorten the preheating time of the water point, reduce heat loss in the pipeline during the preheating process, and improve the user experience.

[0051] In some embodiments of this utility model, such as Figure 1 As shown, the four-way reversing valve 120 and the bypass pipe 130 can be installed inside the water heater 110, which facilitates unified production and debugging by the water heater manufacturer and is also convenient for users. The water heater 110 is provided with an inlet end L, a first converter end M, and a second converter end N. The inlet end L is connected to the cold water pipe 111, the first converter port E is connected to the first converter end M, the second converter port C is connected to the second converter end N, the first end of the heating pipe 140 is connected to the first converter end M, and the second end of the heating pipe 140 is connected to the second converter end N.

[0052] In some embodiments of this utility model, the four-way reversing valve and bypass pipe can also be installed outside the water heater, which makes it convenient for users who have already installed conventional water heaters (water heaters without four-way reversing valves and bypass pipes) to achieve the functions of this utility model by installing four-way reversing valves and bypass pipes later. Figure 4 This is a schematic diagram of another hot water preheating system provided by this utility model. The difference between this embodiment and the previous embodiment is that the four-way reversing valve and the bypass pipe are located outside the water heater. This embodiment describes the parts that differ from the previous embodiment, while the same parts will not be repeated here. Figure 4 As shown, the four-way reversing valve 120 and the bypass pipe 130 are located outside the water heater 110. The water heater 110 is provided with an inlet A and an outlet B. The inlet A is connected to the cold water pipe 111, and the outlet B is connected to the hot water pipe 112. The inlet D of the four-way reversing valve 120 is connected to the outlet B.

[0053] In some embodiments of this utility model, such as Figure 1 , 4 As shown, a one-way valve 131 is provided on the bypass pipe 130 to allow water in the bypass pipe 130 to flow unidirectionally from the bypass port S to the cold water pipe 111. It should be noted that in some embodiments of this utility model, if the four-way reversing valve 120 has a flow-limiting function, then the one-way valve 131 is not required.

[0054] In some embodiments of this utility model, such as Figure 1 , 4 As shown, the hot water preheating system also includes at least two preheating signal triggers 151. Each preheating signal trigger 151 is associated with a corresponding water point 150 and is communicatively connected to the water heater 110. Users can send preheating signals to the water heater 110 directly through the preheating signal triggers 151 or via a relay (e.g., a client). This invention is not limited in this respect. It should be noted that in other embodiments of this invention, preheating signal triggers may not be required. The preheating signal can also be triggered by repeatedly opening and closing the current water point within a short period (i.e., momentary triggering). This invention is not limited in this respect.

[0055] In some embodiments of this utility model, such as Figure 1 , 4As shown, a temperature sensor 152 is also installed at the connection point between the water point 150 and the heating pipe 140 to collect the hot water temperature at the connection point. The temperature sensor 152 is communicatively connected to the water heater 110 and uploads the collected hot water temperature to the water heater 110. During the preheating process, the water heater 110 can determine whether a preheating end signal, indicating that hot water has arrived at the current water point, has been detected based on the hot water temperature collected by the temperature sensor 152, and stop the preheating operation when the preheating end signal is detected. For example, when the hot water temperature at the current water point reaches the preset range of the user's set temperature (e.g., set temperature ±3℃), it indicates that hot water has arrived at the current water point, and the preheating operation is stopped at this time. It should be noted that in other embodiments of this utility model, the connection position between the water point 150 and the heating pipe 140 may not be equipped with a temperature sensor 152. During the preheating process, the preheating time or the circulating water flow rate is monitored in real time. When the preheating time reaches the preset preheating time corresponding to the current water point or the circulating water flow rate reaches the preset circulating flow rate corresponding to the current water point, it indicates that hot water has arrived at the current water point, and the preheating operation is stopped at this time.

[0056] In some embodiments of this utility model, such as Figure 1 , 4 As shown, the water heater 110 also includes a circulating water pump 113 and a heating unit 114. The inlet of the circulating water pump 113 is connected to the cold water pipe 111, the outlet of the circulating water pump 113 is connected to the inlet of the heating unit 114, and the outlet of the heating unit 114 is connected to the hot water pipe 112. The circulating water pump 113 is used to increase the water pressure in the pipeline during normal hot water use and preheating. The heating unit 114 is used to heat the cold water entering the water heater 110.

[0057] In some embodiments of this utility model, the water heater can be a gas water heater, and the heating unit 114 includes a burner and a heat exchanger. The inlet of the heat exchanger is connected to the outlet of the circulating water pump 113, and the outlet of the heat exchanger is connected to the hot water pipe 112. The gas input to the burner is ignited in the burner, generating high-temperature flue gas, which heats the heat exchanger. As cold water flows through the heat exchanger, the heat exchanger exchanges heat with the cold water, thus heating the cold water.

[0058] In some embodiments of this utility model, the water heater can be an electric water heater, and the heating unit 114 includes an inner tank and an electric heating element. The inlet of the inner tank is connected to the outlet of the circulating water pump 113, and the outlet of the inner tank is connected to the hot water pipe 112. The inner tank is used to store hot water, and the electric heating element is disposed inside the inner tank for heating the water in the inner tank.

[0059] It should be noted that, in the above embodiments, the water heater shows some structures associated with this solution. Those skilled in the art should understand that the water heater may also include other structures. For example, a gas water heater may also include a burner, an igniter, a flow sensor, an inlet water temperature sensor, an outlet water temperature sensor, etc., and an electric water heater may also include an anode rod, a flow sensor, an inlet water temperature sensor, an outlet water temperature sensor, etc. This utility model does not limit these components.

[0060] This invention also provides a preheating method, which is applied to a water heater in a hot water preheating system as provided in any of the foregoing embodiments of this invention, and can be executed by the main controller of the water heater. Figure 5 A flowchart illustrating a preheating method provided by this utility model is shown below. Figure 5 As shown, the preheating method includes:

[0061] S101. In response to the preheating signal of the current water point, the length of the heating pipe between the current water point and the first converter port is obtained as the first pipeline length, and the length of the heating pipe between the current water point and the second converter port is obtained as the second pipeline length.

[0062] refer to Figures 1-4 In this embodiment of the present invention, when the water heater 110 receives a preheating signal from the current water point, it acquires the length of the heating pipe 140 between the current water point and the first converter port E as the first pipe length PL1, and acquires the length of the heating pipe 140 between the current water point and the second converter port C as the second pipe length PL2. The current water point can be one of at least two water points. For example, the preheating signal can be triggered by a preheating signal trigger 151 associated with the current water point, or it can be triggered by the current water point being turned on and off repeatedly in a short period of time (i.e., momentary triggering). This embodiment of the present invention does not limit this.

[0063] S102. Compare the length of the first pipeline with the length of the second pipeline.

[0064] After obtaining the lengths of the first pipeline PL1 and the second pipeline PL2, the lengths PL1 and PL2 are compared to determine their relative lengths. It should be noted that, to avoid situations where the first pipeline length PL1 and the second pipeline length PL2 are equal, during pipeline laying and water point installation, the first pipeline length PL1 and the second pipeline length PL2 for each water point can be set to be unequal.

[0065] S103. When the length of the first pipeline is less than the length of the second pipeline, the four-way reversing valve is controlled to work in the first working state. In the first working state, the inlet of the four-way reversing valve is connected to the first reversing port, and the bypass port is connected to the second reversing port, so as to form a first-direction circulating preheating circuit that flows from the first reversing port through the heating pipe, the second reversing port, the bypass port and the bypass pipe back to the cold water pipe of the water heater.

[0066] When the length of the first pipeline PL1 is less than the length of the second pipeline PL2, the four-way reversing valve 120 is controlled to operate in the first operating state. In the first operating state, the inlet D of the four-way reversing valve 120 is connected to the first switching port E, and the bypass port S is connected to the second switching port C, so as to form a first direction in which the water flows back from the first switching port E through the heating pipe 140, the second switching port C, the bypass port S, and the bypass pipe 130 to the cold water pipe 111 of the water heater 110. Figure 1 , 4 The circulating preheating water circuit (in the counterclockwise direction) is in the middle.

[0067] S104. When the length of the second pipeline is less than the length of the first pipeline, control the four-way reversing valve to work in the second working state. In the second working state, the inlet of the four-way reversing valve is connected to the second reversing port, and the bypass port is connected to the first reversing port, so as to form a second-direction circulating preheating circuit that flows from the second reversing port through the heating pipe, the first reversing port, the bypass port and the bypass pipe back to the cold water pipe of the water heater.

[0068] When the length of the second pipeline PL2 is less than the length of the first pipeline PL1, the four-way reversing valve 120 is controlled to operate in a second working state. In the second working state, the inlet D of the four-way reversing valve 120 is connected to the second reversing port C, and the bypass port S is connected to the first reversing port E, so as to form a second direction of return from the second reversing port C through the heating pipe 140, the first reversing port E, the bypass port S, and the bypass pipe 130 to the cold water pipe 111 of the water heater 110. Figure 1 , 4 The circulating preheating water circuit (clockwise direction) is in the middle.

[0069] S105. Perform a preheating operation in response to a preheating signal, and stop the preheating operation when a preheating end signal indicating that hot water has arrived at the current water point is determined.

[0070] While controlling the operation of the four-way reversing valve 120, the water heater 110 responds to the preheating signal and performs a preheating operation, starting the water heater 110 and beginning heating. During the preheating process, the preheating end signal is monitored in real time. When a preheating end signal indicating that hot water has arrived at the current water point is determined, the preheating operation stops. For example, during the preheating process, the hot water temperature, preheating time, or circulating water flow rate at the current water point is monitored in real time. When the hot water temperature at the current water point reaches a preset range of the user's set temperature (e.g., set temperature ±3℃), the preheating time reaches the preset preheating time corresponding to the current water point, or the circulating water flow rate reaches the preset circulating flow rate corresponding to the current water point, it indicates that hot water has arrived at the current water point, and the preheating operation stops at this time.

[0071] The preheating method provided by this utility model, in response to the preheating signal of the current water point, obtains the length of the heating pipe between the current water point and the first converter port as the first pipe length PL1, and obtains the length of the heating pipe between the current water point and the second converter port as the second pipe length PL2. The first pipe length PL1 and the second pipe length PL2 are compared. When the first pipe length PL1 is less than the second pipe length PL2, the four-way reversing valve is controlled to operate in the first working state. In the first working state, the inlet of the four-way reversing valve is connected to the first converter port, and the bypass port is connected to the second converter port, to form a first-direction circulating preheating circuit from the first converter port through the heating pipe, the second converter port, the bypass port, and the bypass pipe back to the cold water pipe of the water heater. When the second pipe length PL2 is less than the first pipe length PL1, the four-way reversing valve is controlled to operate... In the second operating state, the inlet of the four-way reversing valve is connected to the second reversing port, and the bypass port is connected to the first reversing port, forming a second-direction circulating preheating circuit that flows from the second reversing port through the heating pipe, the first reversing port, the bypass port, and the bypass pipe back to the cold water pipe of the water heater. It performs preheating operation in response to a preheating signal and stops the preheating operation when a preheating end signal indicating that hot water has reached the current water point is detected. Before each preheating cycle, the shortest heating pipe length is selected based on a comparison of the lengths of the heating pipes between the current water point and the first and second reversing ports. Through the reversing action of the four-way reversing valve, a corresponding circulating preheating circuit is formed, and then preheating occurs. This ensures that the preheated hot water reaches the current water point through the shortest pipe, shortening the preheating time at the water point, reducing heat loss in the pipeline during preheating, and improving the user experience.

[0072] Figure 6 This is a flowchart of another preheating method provided by the present invention. This embodiment elaborates on the preheating method in the foregoing embodiments. This preheating method is applied to a water heater in a hot water preheating system as provided in any of the foregoing embodiments of the present invention, and can be executed by the main controller of the water heater. Figure 6 As shown, the preheating method includes:

[0073] S201, Receive the preheating signal from the current water point.

[0074] refer to Figures 1-4 For example, the preheating signal can be triggered by the preheating signal trigger 151 associated with the current water point, or it can be triggered by the current water point being turned on and off repeatedly in a short period of time (i.e., jogging trigger). This embodiment of the present invention does not limit the scope of the signal.

[0075] S202. Obtain the cycle preheating record.

[0076] For example, at the end of each preheating, the water heater 110 records the preheating information in the memory of the main controller. The preheating information may include the water point corresponding to the preheating signal, the direction of the circulating preheating water path, the preheating end time, etc. This utility model embodiment does not limit the scope of the invention.

[0077] S203. Determine the end time of the previous cycle preheating from the cycle preheating record.

[0078] The preheating information of the previous cycle preheating is determined from the cycle preheating record, including the water point corresponding to the preheating signal, the direction of the circulating preheating water circuit, and the end time T. end wait.

[0079] S204. Calculate the time interval between the end time of the previous preheating cycle and the reception time of the preheating signal at the current water point.

[0080] The receiving time T of the preheating signal at the current water point rec Subtract the end time T of the previous preheating cycle end The end time T of the previous preheating cycle is obtained. end The reception time T of the preheating signal to the current water point rec The interval T between them.

[0081] S205. Determine whether the interval duration is greater than the preset duration.

[0082] Determine the end time T of the previous preheating cycle. end The reception time T of the preheating signal to the current water point rec Is the interval T between them greater than the preset duration T? set (For example, 5 mins). If yes, proceed to step S206; otherwise, proceed to step S209.

[0083] S206. Compare the length of the first pipeline with the length of the second pipeline.

[0084] If the interval is longer than a preset time, the length of the heating pipe 140 between the current water point and the first converter port E is obtained as the first pipe length PL1, and the length of the heating pipe 140 between the current water point and the second converter port C is obtained as the second pipe length PL2. The first pipe length PL1 and the second pipe length PL2 are compared to determine their relative lengths. If the first pipe length PL1 is less than the second pipe length PL2, step S207 is executed; if the second pipe length PL2 is less than the first pipe length PL1, step S208 is executed.

[0085] S207. Control the four-way reversing valve to operate in the first working state, forming a circulating preheated water circuit in the first direction.

[0086] When the length of the first pipeline PL1 is less than the length of the second pipeline PL2, the four-way reversing valve 120 is controlled to operate in the first operating state. In the first operating state, the inlet D of the four-way reversing valve 120 is connected to the first switching port E, and the bypass port S is connected to the second switching port C, so as to form a first direction in which the water flows back from the first switching port E through the heating pipe 140, the second switching port C, the bypass port S, and the bypass pipe 130 to the cold water pipe 111 of the water heater 110. Figure 1 , 4 The circulating preheating water circuit (in the counterclockwise direction) is in the middle.

[0087] S208 controls the four-way reversing valve to operate in the second working state, forming a second-direction circulating preheating water circuit.

[0088] When the length of the second pipeline PL2 is less than the length of the first pipeline PL1, the four-way reversing valve 120 is controlled to operate in a second working state. In the second working state, the inlet D of the four-way reversing valve 120 is connected to the second reversing port C, and the bypass port S is connected to the first reversing port E, so as to form a second direction of return from the second reversing port C through the heating pipe 140, the first reversing port E, the bypass port S, and the bypass pipe 130 to the cold water pipe 111 of the water heater 110. Figure 1 , 4 The circulating preheating water circuit (clockwise direction) is in the middle.

[0089] S209. Determine the target water point that triggered the previous cycle preheating and the cycle direction of the previous cycle preheating from the cycle preheating record.

[0090] If the interval duration T is less than or equal to the preset duration T set Then, the target water point that triggered the previous cycle preheating and the cycle direction of the previous cycle preheating are determined from the cycle preheating record. If the cycle direction of the previous cycle preheating is the first direction, step S210 is executed; if the cycle direction of the previous cycle preheating is the second direction, step S219 is executed.

[0091] S210. Obtain the length of the heating pipe between the target water point and the first converter port as the third pipeline length FL1.

[0092] When the circulation direction of the previous preheating cycle is the first direction, the length of the heating pipe between the target water point and the first exchange port E is obtained as the third pipeline length FL1.

[0093] S211. Compare the length of the first pipeline with the length of the third pipeline.

[0094] The length of the first pipeline PL1 is compared with the length of the third pipeline FL1. If the length of the first pipeline PL1 is less than or equal to the length of the third pipeline FL1, step S212 is executed; if the length of the first pipeline PL1 is greater than the length of the third pipeline FL1, step S215 is executed.

[0095] S212. Obtain the water temperature at the current water point, calculate the temperature difference between the user's set temperature and the current water temperature, and determine whether the temperature difference is within the preset temperature difference range.

[0096] When the length of the first pipe PL1 is less than or equal to the length of the third pipe FL1, obtain the water temperature W at the current water point. t Calculate the user's set temperature W set Water temperature W at the current water point t temperature difference W set -W t And determine the temperature difference W set -W t Whether it is within the preset temperature difference range W (e.g., ±3℃) (i.e., judging W) set -W t If yes, proceed to step S213; otherwise, proceed to step S214.

[0097] S213. Maintain the water heater in standby mode.

[0098] At temperature difference W set -W t When the temperature difference is within the preset range W, it means that the target water point has been preheated within the preset time, and the hot water generated by the preheating has filled the length of the heating pipe (i.e., the first pipe length PL1) between the current water point and the first converter port E. The water temperature in the current pipe meets the user's needs. At this time, the water heater is kept in standby mode to avoid repeated preheating and energy waste, thus improving energy efficiency.

[0099] S214. Control the four-way reversing valve to form a circulating preheating hot water circuit with the same circulation direction as the previous preheating cycle.

[0100] At temperature difference W set -Wt If the temperature difference is not within the preset temperature difference range W, it means that the target water point has been preheated within the preset time period, and the hot water generated by the preheating has filled the length of the heating pipe between the current water point and the first exchange port E (i.e., the first pipe length PL1). However, the water temperature in the current pipe does not meet the user's needs. In this case, the four-way reversing valve 120 is controlled to operate, forming a circulating preheating hot water circuit with the same circulation direction as the previous preheating cycle (i.e., the first direction).

[0101] S215. Calculate the difference between the length of the first pipeline and the length of the third pipeline as the first length, where the first length is the length of the heating pipe between the current water point and the target water point.

[0102] When the length of the first pipeline PL1 is greater than the length of the third pipeline FL1, it indicates that the target water point has been preheated within the preset time period, but there is a section of cold water between the current water point and the target water point. At this time, the difference between the length of the first pipeline PL1 and the length of the third pipeline FL1 is calculated as the first length PL1-FL1, and the first length PL1-FL1 is the length of the heating pipe between the current water point and the target water point.

[0103] S216. Compare the first length with the second pipeline length.

[0104] The first length PL1-FL1 is compared with the second pipe length PL2. If the first length PL1-FL1 is greater than the second pipe length PL2, step S217 is executed; if the first length PL1-FL1 is less than or equal to the second pipe length PL2, step S218 is executed.

[0105] S217. Control the four-way reversing valve to operate in the second working state, forming a second-direction circulating preheating water circuit.

[0106] When the first length PL1-FL1 is greater than the second pipe length PL2, it means that the length of the heating pipe between the current water point and the target water point (the first length PL1-FL1) is greater than the length PL2 of the heating pipe between the current water point and the second converter port C. The four-way reversing valve 120 is controlled to work in the second working state, forming a second-direction circulating preheating water circuit (that is, forming a circulating preheating water circuit in the opposite direction to the previous circulating preheating), so that the preheated hot water reaches the current water point through the shortest pipe, reducing the preheating time of the more distant water point, reducing the heat loss in the pipe during the preheating process, and improving the user experience.

[0107] S218. Control the four-way reversing valve to operate in the first working state, forming a circulating preheated water circuit in the first direction.

[0108] When the first length PL1-FL1 is less than or equal to the second pipe length PL2, it means that the length of the heating pipe between the current water point and the target water point (the first length PL1-FL1) is less than or equal to the length PL2 of the heating pipe between the current water point and the second converter port C. The four-way reversing valve 120 is controlled to work in the first working state to form a circulating preheating water circuit in the first direction (that is, to form a circulating preheating water circuit in the same direction as the previous circulating preheating), so that the preheated hot water reaches the current water point through the shortest pipe, reducing the preheating time of the more distant water point, reducing the heat loss in the pipe during the preheating process, and improving the user experience.

[0109] S219. Obtain the length of the heating pipe between the target water point and the second converter port as the fourth pipeline length.

[0110] When the circulation direction of the previous preheating cycle was the second direction, the length of the heating pipe between the target water point and the second converter port C is obtained as the fourth pipeline length FL2.

[0111] S220. Compare the length of the second pipeline with the length of the fourth pipeline.

[0112] When the length of the second pipe PL2 is less than or equal to the length of the fourth pipe FL2, execute step S212 to obtain the water temperature W at the current water point. t Calculate the user's set temperature W set Water temperature W at the current water point t temperature difference W set -W t And determine the temperature difference W set -W t Is it within the preset temperature difference range W (e.g., ±3℃)? If yes, proceed to step S213; otherwise, proceed to step S214. That is, within the temperature difference W... set -W t When the temperature difference is within the preset temperature range W, it means that the target water point has been preheated within the preset time period, and the preheated hot water has filled the length of the heating pipe between the current water point and the second converter port C (i.e., the second pipe length PL2). Furthermore, the water temperature in the current pipe meets the user's needs. In this case, the water heater remains in standby mode to avoid repeated preheating and energy waste, thus improving energy efficiency. Within the temperature difference W... set -W t If the temperature difference is not within the preset temperature difference range W, it means that the target water point has been preheated within the preset time period, and the hot water generated by the preheating has filled the length of the heating pipe between the current water point and the second exchange port C (i.e., the second pipe length PL2). However, the water temperature in the current pipe does not meet the user's needs. In this case, the four-way reversing valve 120 is controlled to operate, forming a circulating preheating hot water circuit with the same circulation direction as the previous preheating cycle (i.e., the second direction).

[0113] When the length of the second pipeline PL2 is greater than the length of the fourth pipeline FL2, proceed to step S221.

[0114] S221. Calculate the difference between the length of the second pipeline and the length of the fourth pipeline as the second length. The second length is the length of the heating pipe between the current water point and the target water point.

[0115] When the length of the second pipeline PL2 is greater than the length of the fourth pipeline FL2, it indicates that the target water point has been preheated within the preset time period, but there is a section of cold water between the current water point and the target water point. At this time, the difference between the length of the second pipeline PL2 and the length of the fourth pipeline FL2 is calculated as the second length PL2-FL2, and the second length PL2-FL2 is the length of the heating pipe between the current water point and the target water point.

[0116] S222. Compare the second length with the first pipeline length.

[0117] The second length PL2-FL2 is compared with the first pipe length PL1. If the second length PL2-FL2 is greater than the first pipe length PL1, step S223 is executed; if the second length PL2-FL2 is less than or equal to the first pipe length PL1, step S224 is executed.

[0118] S223. Control the four-way reversing valve to work in the first working state, forming a circulating preheated water circuit in the first direction.

[0119] When the second length PL2-FL2 is greater than the first pipeline length PL1, it means that the length of the heating pipe between the current water point and the target water point (the second length PL2-FL2) is greater than the length PL1 of the heating pipe between the current water point and the first exchange port E. The four-way reversing valve 120 is controlled to work in the first working state, forming a circulating preheating water circuit in the first direction (that is, forming a circulating preheating water circuit in the opposite direction to the previous circulating preheating circuit). This allows the preheated hot water to reach the current water point through the shortest pipe, reducing the preheating time of the more distant water point, reducing heat loss in the pipeline during the preheating process, and improving the user experience.

[0120] S224. Control the four-way reversing valve to operate in the second working state, forming a second-direction circulating preheating water circuit.

[0121] When the second length PL2-FL2 is less than or equal to the first pipe length PL1, it means that the length of the heating pipe between the current water point and the target water point (the second length PL2-FL2) is less than or equal to the length PL1 of the heating pipe between the current water point and the first exchange port E. The four-way reversing valve 120 is controlled to work in the second working state, forming a second-direction circulating preheating water circuit (i.e., forming a circulating preheating water circuit with the same circulation direction as the previous circulating preheating), so that the preheated hot water reaches the current water point through the shortest pipe, reducing the preheating time of the more distant water point, reducing the heat loss in the pipe during the preheating process, and improving the user experience.

[0122] S225. Perform a preheating operation in response to a preheating signal, and stop the preheating operation when a preheating end signal indicating that hot water has arrived at the current water point is determined.

[0123] While controlling the four-way reversing valve 120 to form a circulating preheating circuit, the water heater 110 responds to the preheating signal and performs a preheating operation, starting to heat water. During the preheating process, the preheating end signal is monitored in real time. When a preheating end signal indicating that hot water has arrived at the current water point is determined, the preheating operation stops. For example, during the preheating process, the hot water temperature, preheating time, or circulating water flow rate at the current water point is monitored in real time. When the hot water temperature at the current water point reaches a preset range of the user's set temperature (e.g., set temperature ±3℃), the preheating time reaches the preset preheating time corresponding to the current water point, or the circulating water flow rate reaches the preset circulating flow rate corresponding to the current water point, it indicates that hot water has arrived at the current water point, and the preheating operation stops at this time.

[0124] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0125] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0126] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without any inventive effort, and these embodiments will all fall within the scope of protection of this utility model.

Claims

1. A hot water preheating system, characterized by, include: A water heater (110) includes a cold water pipe (111) and a hot water pipe (112), wherein the cold water pipe (111) is used to input cold water and the hot water pipe (112) is used to output hot water; A four-way reversing valve (120) includes an inlet D, a bypass port S, a first switching port E, and a second switching port C. The inlet D of the four-way reversing valve (120) is connected to the hot water pipe (112), and the four-way reversing valve (120) is communicatively connected to the water heater (110). A bypass pipe (130) is provided, with its inlet connected to the bypass port S and its outlet connected to the cold water pipe (111). A heating pipe (140) is provided, with its first end connected to the first exchange port E and its second end connected to the second exchange port C. There are at least two water points (150), the hot water inlet of the water point (150) is connected to the heating pipe (140), and the cold water inlet of the water point (150) is connected to the cold water pipe (111).

2. The hot water preheating system of claim 1, wherein The four-way reversing valve (120) and the bypass pipe (130) are disposed inside the water heater (110); The water heater (110) is provided with an inlet end L, a first converter end M, and a second converter end N. The inlet end L is connected to the cold water pipe (111), the first converter port E is connected to the first converter end M, the second converter port C is connected to the second converter end N, the first end of the heating pipe (140) is connected to the first converter end M, and the second end of the heating pipe (140) is connected to the second converter end N.

3. The hot water preheating system according to claim 1, characterized in that, The four-way reversing valve (120) and the bypass pipe (130) are located outside the water heater (110); The water heater (110) is provided with an inlet A and an outlet B. The inlet A is connected to the cold water pipe (111), and the outlet B is connected to the hot water pipe (112). The inlet D of the four-way reversing valve (120) is connected to the outlet B.

4. A hot water preheating system according to any one of claims 1-3, characterized in that A one-way valve (131) is provided on the bypass pipe (130) to allow water in the bypass pipe (130) to flow unidirectionally from the bypass port S to the cold water pipe (111).

5. The hot water preheating system according to any one of claims 1-3, wherein It also includes at least two preheating signal triggers (151), each preheating signal trigger (151) being associated with a corresponding water point (150), and the preheating signal triggers (151) being communicatively connected to the water heater (110).

6. The hot water preheating system according to any one of claims 1-3, wherein A temperature sensor (152) is also provided at the connection position between the water point (150) and the heating pipe (140), and the temperature sensor (152) is communicatively connected to the water heater (110).

7. The hot water preheating system according to any one of claims 1-3, characterized in that, The water heater (110) also includes a circulating water pump (113) and a heating unit (114); The inlet of the circulating water pump (113) is connected to the cold water pipe (111), the outlet of the circulating water pump (113) is connected to the inlet of the heating unit (114), and the outlet of the heating unit (114) is connected to the hot water pipe (112).

8. The hot water preheat system of claim 7, wherein, The heating unit (114) includes a burner and a heat exchanger; The inlet of the heat exchanger is connected to the outlet of the circulating water pump, and the outlet of the heat exchanger is connected to the hot water pipe. The burner is used to ignite combustible gas to heat the heat exchanger.

9. The hot water preheat system of claim 7, wherein, The heating unit (114) includes an inner liner and an electric heating element; The inlet of the inner tank is connected to the outlet of the circulating water pump, and the outlet of the inner tank is connected to the hot water pipe. The inner tank is used to store hot water, and the electric heating tube is installed inside the inner tank to heat the water in the inner tank.

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