Heat recovery device for a water heater, control method and readable storage medium

Abstract

The present application relates to the technical field of household appliances, and discloses a heat recovery device for a water heater, a control method and a readable storage medium, the heat recovery device comprising: an exhaust pipe, an inside of the exhaust pipe being formed with an exhaust cavity for discharging exhaust gas of the water heater; a heat recovery assembly arranged in the exhaust cavity, the heat recovery assembly comprising a heat exchange shell, a heat recovery pipe and a heat-conducting medium, an inside of the heat exchange shell being formed with a heat exchange cavity, the heat recovery pipe and the heat-conducting medium being arranged in the heat exchange cavity, the heat recovery pipe performing heat exchange with the exhaust gas in the exhaust cavity through the heat-conducting medium, the heat recovery assembly further comprising a circulating pump, the circulating pump being arranged in the heat exchange shell and being in communication with the heat-conducting medium, the circulating pump controlling the heat exchange efficiency of the heat recovery pipe and the exhaust gas by controlling the circulation efficiency of the heat-conducting medium. The present application proposes a mode of controlling the flow of the heat-conducting medium by the circulating pump, controls the heat exchange efficiency of the heat recovery pipe and the exhaust gas, realizes the heat recovery effect on the exhaust gas, and reduces the condensate water generated by the heat dissipation of the exhaust gas.

Description

Technical Field

[0001] This invention relates to the field of household appliance technology, and more specifically to a heat recovery device, control method, and readable storage medium for water heaters. Background Technology

[0002] As customers' demands for quality of life continue to rise, their requirements for the energy efficiency of gas water heaters are increasing. Therefore, condensing water heaters have become the mainstream in the market. Due to the increased energy efficiency requirements for water heaters, the gas thermal efficiency of the water heaters must also be improved, and the heat recovery rate of the exhaust gas also needs to be increased. However, heat recovery of the exhaust gas leads to a large amount of condensate forming when the water vapor in the exhaust gas cools down. The water heater then needs an external drain pipe to discharge this condensate, affecting the customer's daily user experience and product satisfaction. Summary of the Invention

[0003] In view of this, the present invention provides a heat recovery device for a water heater to solve the technical problem that the exhaust gas recovery in the prior art cannot simultaneously take into account heat recovery and condensate treatment.

[0004] In a first aspect, the present invention provides a heat recovery device for a water heater, the heat recovery device comprising: a flue pipe having a flue chamber formed inside the flue pipe for discharging exhaust gas from the water heater; a heat recovery assembly disposed in the flue chamber, the heat recovery assembly comprising a heat exchange shell, a heat recovery pipe, and a heat transfer medium, the heat exchange shell having a heat exchange chamber formed inside the heat exchange shell, the heat recovery pipe and the heat transfer medium both being disposed in the heat exchange chamber, the heat recovery pipe exchanging heat with the exhaust gas in the flue chamber through the heat transfer medium, the heat recovery assembly further comprising a circulation pump disposed in the heat exchange shell and connected to the heat transfer medium, the circulation pump controlling the heat exchange efficiency between the heat recovery pipe and the exhaust gas by controlling the circulation efficiency of the heat transfer medium.

[0005] Beneficial Effects: This embodiment proposes a method of controlling the flow of the heat transfer medium through a circulating pump to control the heat exchange efficiency between the heat recovery pipe and the waste gas. This not only achieves heat recovery from the waste gas but also reduces the condensation caused by excessive heat dissipation from the waste gas. During the heat recovery process, the speed of the circulating pump can be controlled by a PWM controller, allowing the heat transfer medium in the heat recovery device to flow or stop. When the heat transfer medium flows, heat exchange occurs between the heat recovery pipe and the waste gas. The amount of heat exchange between the heat recovery pipe and the waste gas is positively correlated with the speed of the circulating pump. The heat transfer medium is a fluid with high thermal conductivity. Its function is to come into thermal contact with the waste gas and absorb heat from it, releasing the absorbed heat to the water in the heat recovery pipe, thereby achieving heat exchange and recovery between the waste gas and the water supplied to the heat exchanger.

[0006] In one optional embodiment, the heat exchange chamber is provided with a heat recovery tube chamber and a heat transfer medium chamber, and a circulation channel is provided between the heat recovery tube chamber and the heat transfer medium chamber, with a circulation pump located in the circulation channel.

[0007] Beneficial effects: By separating the heat recovery tube chamber and the heat transfer medium, and controlling the circulation flow of the heat transfer medium through a circulating pump, the natural heat exchange between the heat recovery tube and the heat transfer medium can be reduced. Thus, the heat exchange between the heat recovery tube and the heat transfer medium can be controlled by the circulating pump, keeping the heat exchange efficiency between the heat recovery tube and the exhaust gas within a controllable range.

[0008] In one optional embodiment, a heat insulation cylinder is provided in the middle of the heat exchange chamber, a heat recovery tube chamber is formed inside the heat insulation cylinder, a heat transfer medium chamber is formed outside the heat insulation cylinder, a heat transfer medium inlet is provided at the bottom of the heat insulation cylinder, a heat transfer medium outlet is provided at the top of the heat insulation cylinder, and a circulation pump is provided at the heat transfer medium inlet and / or heat transfer medium outlet.

[0009] Beneficial effects: The heat insulation cylinder can isolate the heat recovery pipe from the heat transfer medium, thereby reducing the natural heat exchange between the heat recovery pipe and the heat transfer medium. This allows the heat exchange between the heat recovery pipe and the heat transfer medium to be controlled by a circulating pump, keeping the heat exchange efficiency between the heat recovery pipe and the exhaust gas within a controllable range.

[0010] In one optional embodiment, the heat recovery assembly further includes a temperature and humidity detection module, which is disposed in the heat exchange shell and located in the flue gas chamber, for detecting the dew point temperature of the exhaust gas.

[0011] Beneficial effects: The temperature and humidity module acquires the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater and outputs it to the main control chip of the water heater. The main control chip calculates the dew point temperature of the exhaust gas based on the temperature and humidity information, and then controls the operation of the heat recovery device according to the dew point temperature of the exhaust gas to recover the heat in the process of the high-temperature exhaust gas dropping from its original temperature to the dew point temperature. The recovered heat is used to preheat the water entering the water heater.

[0012] In one alternative embodiment, the heat recovery pipe is connected in series to the water inlet pipe of the water heater to preheat the water entering the water heater, and the heat recovery pipe is provided with a flow section located in the heat exchange chamber and spiraling downward.

[0013] Beneficial effects: By setting the heat recovery tube with a flow section located in the heat exchange chamber and spiraling downward, the water in the heat recovery tube and the rising heat transfer medium can be counteracted, which can increase the heat exchange time and area between the water in the heat recovery tube and the rising heat transfer medium, thereby improving the heat exchange efficiency between the water in the heat recovery tube and the rising heat transfer medium.

[0014] Secondly, the present invention provides a control method for a water heater, which is implemented by the heat recovery device for the water heater described in the first aspect above. The control method includes: acquiring exhaust gas emission information; acquiring the working status of the heat recovery pipe; and controlling the circulation pump to drive the circulation or stop the flow of the heat transfer medium based on the exhaust gas emission information and the working status of the heat recovery pipe.

[0015] Beneficial effects: The embodiments of this application propose a method of controlling the flow of heat transfer medium by circulating pump to control the heat exchange efficiency between heat recovery pipe and waste gas. This not only achieves the heat recovery effect of waste gas, but also reduces the phenomenon of condensation caused by excessive heat dissipation from waste gas.

[0016] In one optional implementation, controlling the circulation of the heat transfer medium driven by the circulating pump or stopping its circulation based on the exhaust gas emission information and the operating status of the heat recovery pipe specifically includes: acquiring the dew point temperature and real-time temperature of the exhaust gas; comparing the real-time temperature of the exhaust gas with the dew point temperature; controlling the circulation efficiency of the heat transfer medium through the circulating pump and controlling the heat exchange efficiency between the heat recovery pipe and the exhaust gas if the real-time temperature is greater than the dew point temperature; and stopping the circulation of the heat transfer medium through the circulating pump if the real-time temperature is less than or equal to the dew point temperature, until the real-time temperature is greater than the dew point temperature.

[0017] Beneficial effects: In the heat recovery device, the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater is obtained by the temperature and humidity module and output to the main control chip of the water heater. The main control chip calculates the dew point temperature of the exhaust gas based on the temperature and humidity information, and then controls the operation of the heat recovery device according to the dew point temperature of the exhaust gas. The heat is recovered during the process of the high-temperature exhaust gas dropping from its original temperature to the dew point temperature, and the recovered heat is used to preheat the water entering the water heater.

[0018] In one optional implementation, obtaining the dew point temperature of the exhaust gas specifically includes: obtaining the real-time temperature and real-time humidity of the exhaust gas; and calculating the dew point temperature of the exhaust gas based on the real-time temperature and real-time humidity.

[0019]

[0020]

[0021] The saturated vapor pressure es is calculated using the real-time temperature T, the actual vapor pressure e is calculated using the humidity RH, and the dew point temperature Td is calculated using the actual vapor pressure e.

[0022] Beneficial effects: In the heat recovery device, the principle of phase equilibrium between gas and water vapor is utilized. If the temperature of the exhaust gas is not lower than its dew point temperature, condensation will not occur, thus preventing the generation of condensate. A temperature and humidity module acquires the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater and outputs it to the water heater's main control chip. The main control chip calculates the dew point temperature of the exhaust gas based on the temperature and humidity information, and then controls the operation of the heat recovery device according to the dew point temperature of the exhaust gas. This recovers the heat generated during the process of the high-temperature exhaust gas decreasing from its original temperature to its dew point temperature, and uses the recovered heat to preheat the water entering the water heater.

[0023] In one optional implementation, controlling the circulation of the heat transfer medium driven by the circulating pump to circulate or stop the flow based on the exhaust gas emission information and the operating status of the heat recovery pipe further includes: obtaining the required water temperature of the heat recovery pipe; calculating the temperature difference between the real-time temperature and the dew point temperature; and controlling the power of the circulating pump based on the required water temperature and the temperature difference.

[0024] Beneficial effects: Specifically, when the required water temperature for the heat recovery pipe is high, the speed of the circulation pump is increased; when the required water temperature is low, the speed of the circulation pump is decreased. Specifically, the system monitors whether the exhaust gas temperature is higher than the dew point temperature calculated by the main control chip. If the exhaust gas temperature is less than or equal to the dew point temperature, the PWM wave output to the circulation pump is stopped. At this time, the circulation pump stops running, the heat transfer medium stops flowing, the insulation cylinder blocks the heat transfer between the two sides, the heat of the exhaust gas is not absorbed, the exhaust gas temperature will not drop, and the exhaust gas temperature will not fall below the dew point temperature, preventing condensation from forming inside the water heater. If the exhaust gas temperature is higher than the dew point temperature, the duty cycle of the PWM wave is gradually increased to increase the circulation pump speed until the most suitable circulation pump speed is found.

[0025] Thirdly, the present invention provides a readable storage medium storing computer instructions, which, when executed, implement the water heater control method of the second aspect described above.

[0026] Beneficial effects: The readable storage medium provided in this embodiment, by adopting the water heater control method of the above-described embodiment, has all the technical effects of the water heater control method described above. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1This is a schematic diagram of the structure of a water heater according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the heat recovery device in the water heater shown. Figure 3 This is a flowchart of a water heater control method according to an embodiment of the present invention; Figure 4 This is a flowchart of a water heater control method according to another embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures: 100. Water heater; 10. Water heater body; 20. Smoke exhaust pipe; 21. Smoke exhaust chamber; 30. Heat recovery assembly; 301. Preheating water inlet pipe; 302. Preheating water outlet pipe; 31. Heat exchange shell; 32. Heat recovery pipe; 33. Insulation cylinder; 34. Circulation pump; 35. Temperature and humidity detection module. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be noted that the terms "inner," "upper," "outer," "lower," and "below," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; they can refer to mechanical connection or electrical connection; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to connection within two components; they can refer to wireless connection or wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] To address the issue of condensate drainage in water heaters, various technologies employ drainage solutions such as drain pipes, suction structures, or pumps to remove the condensate. However, these solutions presuppose the formation and discharge of condensate, which can corrode components of the water heater. Furthermore, the condensate drainage system can negatively impact user experience and satisfaction.

[0034] To address the technical problem in related technologies where water heaters cannot simultaneously handle heat recovery and condensate treatment during waste gas recovery, this invention proposes to separately control the heat transfer medium. By controlling the flow of the heat transfer medium, the heat recovery efficiency of the waste gas can be controlled. This allows for the recovery of heat from the waste gas while reducing the excessive heat recovery that leads to condensate production, thus solving the condensate treatment problem at its source.

[0035] The following is combined with Figures 1 to 4 The following describes embodiments of the present invention.

[0036] like Figure 1 and Figure 2 As shown in the embodiments of the present invention, in one aspect, the present invention provides a heat recovery device for a water heater 100, the heat recovery device mainly including a flue pipe 20 and a heat recovery component 30.

[0037] The exhaust pipe 20 forms an exhaust chamber 21 located within the water heater body 10, used to exhaust the waste gas from the water heater 100. The heat recovery component 30 is disposed in the exhaust chamber 21. The heat recovery component 30 includes a heat exchange shell 31, a heat recovery pipe 32, and a heat transfer medium. The heat exchange shell 31 has a heat exchange chamber inside. Both the heat recovery pipe 32 and the heat transfer medium are disposed in the heat exchange chamber. The heat recovery pipe 32 exchanges heat with the waste gas in the exhaust chamber 21 through the heat transfer medium. The heat recovery component 30 also includes a circulation pump 34. The circulation pump 34 is disposed in the heat exchange shell 31 and connected to the heat transfer medium. The circulation pump 34 controls the heat exchange efficiency between the heat recovery pipe 32 and the waste gas by controlling the circulation efficiency of the heat transfer medium, thereby achieving energy-saving effect.

[0038] In this embodiment, a method is proposed to control the flow of the heat transfer medium by circulating pump 34, thereby controlling the heat exchange efficiency between heat recovery pipe 32 and waste gas. This not only achieves heat recovery from waste gas but also reduces the condensation caused by excessive heat dissipation from waste gas. During the heat recovery process, the rotation speed of circulating pump 34 can be controlled by a PWM controller to allow the heat transfer medium in the heat recovery device to flow or stop. When the heat transfer medium flows, heat exchange occurs between heat recovery pipe 32 and waste gas. The amount of heat exchange between heat recovery pipe 32 and waste gas is positively correlated with the rotation speed of circulating pump 34. The heat transfer medium is a fluid with high thermal conductivity. Its function is to come into thermal contact with the waste gas and absorb heat from it, releasing the absorbed heat to the water in heat recovery pipe 32, thus achieving heat exchange and recovery between waste gas and the water supplied by the heat exchanger.

[0039] Specifically, the exhaust gas is a mixture of gas and soot, mainly composed of water vapor, combustion products, and suspended particles, which is harmful to both the environment and human health. Considering the corrosiveness of the exhaust gas, the heat recovery pipe 32 in this embodiment does not directly contact the high-temperature exhaust gas. Moreover, this embodiment can control the heat exchange efficiency between the heat recovery pipe 32 and the exhaust gas by controlling the circulation efficiency of the heat transfer medium according to the circulation pump 34, thereby dynamically adjusting the heat absorption efficiency of the exhaust gas. There is no condensation process, and heat is transferred using the heat transfer medium. The non-high-temperature exhaust gas directly contacts the copper pipe of the heat recovery pipe 32, which can reduce the corrosion of the heat recovery pipe 32 in this embodiment.

[0040] It should be noted that the embodiments of this application do not limit the specific structure of the heat exchange shell 31 and the heat recovery pipe 32 of the heat recovery component 30, because the main function of the heat recovery component 30 is to control the heat exchange efficiency between the heat recovery pipe 32 and the exhaust gas by controlling the heat transfer medium. As for the specific structure of the heat exchange shell 31 and the heat recovery pipe 32, they can be flexibly set according to the actual use environment. For example, the heat exchange shell 31 can be set as a cylindrical or square tube structure, and the heat recovery pipe 32 can be set as a spiral structure or a tortuous structure, etc. These adjustments are all within the protection scope of the embodiments of this application.

[0041] like Figure 1 and Figure 2 As shown, in some embodiments, the heat exchange chamber is provided with a heat recovery tube chamber and a heat transfer medium chamber, and a circulation channel is provided between the heat recovery tube chamber and the heat transfer medium chamber, with the circulation pump 34 disposed in the circulation channel.

[0042] In the above embodiments, by separating the heat recovery tube chamber and the heat transfer medium, and controlling the circulating flow of the heat transfer medium through the circulating pump 34, the natural heat exchange between the heat recovery tube 32 and the heat transfer medium can be reduced. Thus, the circulating pump 34 can be used to control the heat exchange between the heat recovery tube 32 and the heat transfer medium, so that the heat exchange efficiency between the heat recovery tube 32 and the waste gas is within a controllable range.

[0043] Furthermore, the circulation pump 34 can also control the flow heat exchange efficiency of the heat transfer medium, so that the heat of the exhaust gas can be transferred to the heat recovery pipe 32 to preheat the inlet water, and the temperature of the exhaust gas can be prevented from dropping below the dew point temperature, thereby reducing the phenomenon of condensation of exhaust gas and the generation of condensate.

[0044] like Figure 1 and Figure 2 As shown, in some embodiments, a heat insulation cylinder 33 is provided in the middle of the heat exchange chamber, a heat recovery tube chamber is formed inside the heat insulation cylinder 33, a heat conduction medium chamber is formed outside the heat insulation cylinder 33, a heat conduction medium inlet is provided at the bottom of the heat insulation cylinder 33, a heat conduction medium outlet is provided at the top of the heat insulation cylinder 33, and a circulation pump 34 is provided at the heat conduction medium inlet and / or heat conduction medium outlet.

[0045] In this embodiment, the heat insulation cylinder 33 can isolate the heat recovery pipe 32 from the heat transfer medium, thereby reducing the natural heat exchange between the heat recovery pipe 32 and the heat transfer medium. Thus, the heat exchange between the heat recovery pipe 32 and the heat transfer medium can be controlled by the circulating pump 34, so that the heat exchange efficiency between the heat recovery pipe 32 and the waste gas is within a controllable range.

[0046] A circulation pump 34 is provided at the inlet and / or outlet of the heat transfer medium, which can improve the outflow and inflow efficiency of the heat transfer medium and reduce the retention of the heat transfer medium at the outlet and / or inlet.

[0047] like Figure 1 and Figure 2 As shown, in some embodiments, the heat recovery assembly 30 further includes a temperature and humidity detection module 35, which is disposed in the heat exchange shell 31 and located in the exhaust chamber 21, and is used to detect the dew point temperature of the exhaust gas.

[0048] In the above embodiment, the temperature and humidity detection module 35 is used to obtain the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater 100 and output it to the main control chip of the water heater 100. The main control chip calculates the dew point temperature of the exhaust gas through the temperature and humidity information, and then controls the operation of the heat recovery component 30 according to the dew point temperature of the exhaust gas to recover the heat in the process of the high-temperature exhaust gas dropping from its original temperature to the dew point temperature. The recovered heat is used to preheat the water inlet of the water heater 100.

[0049] like Figure 1 and Figure 2As shown, in some embodiments, the heat recovery pipe 32 is connected in series to the water inlet pipe of the water heater 100 to preheat the water inlet of the water heater 100, and the heat recovery pipe 32 is provided with a flow section located in the heat exchange chamber and spiraling downward.

[0050] In the above embodiment, a preheating inlet pipe 301 and a preheating outlet pipe 302 are respectively provided at both ends of the inlet pipe. By setting the heat recovery pipe 32 as a flow section located in the heat exchange chamber and spiraling downward, the water in the heat recovery pipe 32 can form a countercurrent with the rising heat transfer medium, and the heat exchange time and area between the water in the heat recovery pipe 32 and the rising heat transfer medium can be increased, thereby improving the heat exchange efficiency between the water in the heat recovery pipe 32 and the rising heat transfer medium.

[0051] like Figure 3 As shown, in a second aspect, the present invention provides a control method for a water heater 100. The control method for the water heater 100 is implemented through the heat recovery component 30 for the water heater 100 described in the first aspect. The control method for the water heater 100 includes: acquiring exhaust gas emission information; acquiring the working status of the heat recovery pipe 32; and controlling the circulation pump 34 to drive the circulation of the heat transfer medium or stop its flow based on the exhaust gas emission information and the working status of the heat recovery pipe 32.

[0052] In this embodiment, the present application proposes to control the flow of the heat transfer medium by circulating pump 34, thereby controlling the heat exchange efficiency between heat recovery pipe 32 and waste gas. This not only achieves the heat recovery effect of waste gas, but also reduces the phenomenon of condensation caused by excessive heat dissipation from waste gas.

[0053] This application addresses the problem that high-efficiency water heaters 100 are prone to producing condensate, resulting in a poor user experience. It proposes a method using a heat recovery component 30 and a control method based on the dew point temperature of the exhaust gas to keep the exhaust gas temperature of the water heater 100 above the dew point temperature. This prevents condensate production in the exhaust gas and allows for the recovery of excess heat from the exhaust gas to preheat the inlet water, thereby achieving heat recovery from the exhaust gas and improving the thermal efficiency of the water heater 100.

[0054] Specifically, the embodiments of this application, through the above-described control method, can control the exhaust gas of the high-efficiency water heater 100 to always be above the dew point temperature during operation, so that the water vapor in the exhaust gas can be discharged with the exhaust gas, thereby preventing the formation of condensate inside the water heater 100. The water heater 100 does not need to be connected to an external drain pipe to discharge condensate, thereby improving the user experience.

[0055] The embodiments of this application, through the above-described control method, can utilize the heat recovery component 30 to recover the heat from the exhaust gas of the water heater 100 during the operation of the high-efficiency water heater 100. The heat generated during the process of reducing the exhaust gas temperature from its original temperature to the dew point temperature is used to preheat the inlet water of the water heater 100, thereby improving the thermal efficiency of the water heater 100 and meeting the user's requirements for the high-efficiency level of the water heater 100.

[0056] like Figure 3 and Figure 4 As shown, in some embodiments, controlling the circulation pump 34 to drive the circulation of the heat transfer medium or to stop the flow based on the exhaust gas emission information and the working status of the heat recovery pipe 32 specifically includes: obtaining the dew point temperature and real-time temperature of the exhaust gas; comparing the real-time temperature of the exhaust gas with the dew point temperature; controlling the circulation efficiency of the heat transfer medium through the circulation pump 34 and the heat exchange efficiency between the heat recovery pipe 32 and the exhaust gas if the real-time temperature is greater than the dew point temperature; and stopping the circulation of the heat transfer medium through the circulation pump 34 if the real-time temperature is less than or equal to the dew point temperature, until the real-time temperature is greater than the dew point temperature.

[0057] In this embodiment, the heat recovery component 30 utilizes the phase equilibrium principle of gas and water vapor. If the temperature of the exhaust gas is not lower than its dew point temperature, condensation will not occur, thus preventing the generation of condensate. In the heat recovery component 30, a temperature and humidity detection module 35 acquires the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater 100 and outputs it to the main control chip of the water heater 100. The main control chip calculates the dew point temperature of the exhaust gas based on the temperature and humidity information, and then controls the operation of the heat recovery component 30 according to the dew point temperature of the exhaust gas. This recovers the heat generated during the process of the high-temperature exhaust gas decreasing from its original temperature to its dew point temperature, and uses the recovered heat to preheat the water entering the water heater 100.

[0058] Furthermore, if the exhaust gas temperature is higher than the dew point temperature, the duty cycle of the PWM wave is gradually increased to increase the speed of the circulating pump 34 until the most suitable speed of the circulating pump 34 is found.

[0059] like Figure 3 and Figure 4 As shown, in some embodiments, obtaining the dew point temperature of the exhaust gas specifically includes: obtaining the real-time temperature and real-time humidity of the exhaust gas; and calculating the dew point temperature of the exhaust gas based on the real-time temperature and real-time humidity.

[0060]

[0061]

[0062] The saturated vapor pressure es is calculated using the real-time temperature T, the actual vapor pressure e is calculated using the humidity RH, and the dew point temperature Td is calculated using the actual vapor pressure e.

[0063] In this embodiment, the heat recovery device utilizes the phase equilibrium principle of gas and water vapor. If the temperature of the exhaust gas is not lower than its dew point temperature, condensation will not occur, thus preventing the generation of condensate. The temperature and humidity detection module 35 acquires the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater 100 and outputs it to the main control chip of the water heater 100. The main control chip calculates the dew point temperature of the exhaust gas based on the temperature and humidity information, and then controls the operation of the heat recovery component 30 according to the dew point temperature of the exhaust gas. This recovers the heat generated during the process of the high-temperature exhaust gas decreasing from its original temperature to its dew point temperature, and uses the recovered heat to preheat the water entering the water heater 100.

[0064] like Figure 3 and Figure 4 As shown, in some embodiments, controlling the circulation pump 34 to drive the circulation of the heat transfer medium or to stop the flow based on the exhaust gas emission information and the working status of the heat recovery pipe 32 further includes: obtaining the required water temperature of the heat recovery pipe 32; calculating the temperature difference between the real-time temperature and the dew point temperature; and controlling the power of the circulation pump 34 based on the required water temperature and the temperature difference.

[0065] In this embodiment, when the required water temperature of the heat recovery pipe 32 is high, the speed of the circulation pump 34 is increased; when the required water temperature of the heat recovery pipe 32 is low, the speed of the circulation pump 34 is decreased. Specifically, the temperature of the exhaust gas is monitored to determine whether it is higher than the dew point temperature calculated by the main control chip. If the exhaust gas temperature is less than or equal to the dew point temperature, the PWM wave output to the circulation pump 34 is stopped. At this time, the circulation pump 34 stops running, the heat transfer medium stops flowing, the heat insulation cylinder 33 blocks the heat transfer between the two sides, the heat of the exhaust gas is not absorbed, the temperature of the exhaust gas will not drop, the temperature of the exhaust gas will not be lower than the dew point temperature, and condensation will not occur inside the water heater 100. If the exhaust gas temperature is higher than the dew point temperature, the duty cycle of the PWM wave is gradually increased to increase the speed of the circulation pump 34 until the most suitable speed of the circulation pump 34 is found.

[0066] like Figure 4 As shown, the structure and control method of the water heater 100 of this application will be described below through specific embodiments.

[0067] This application embodiment proposes a control method for preheating the inlet water of the water heater 100 by using the exhaust gas of the water heater 100. This application embodiment utilizes the heat recovery component 30 and the control method based on the dew point temperature of the exhaust gas to solve the problem that high-efficiency water heaters 100 are prone to producing condensate.

[0068] Specifically, during the operation of the water heater 100, a large amount of high-temperature exhaust gas is emitted. In this embodiment, a heat recovery component 30 is added to the exhaust pipe 20 that emits high-temperature exhaust gas. The heat recovery component 30 absorbs a large amount of heat from the high-temperature exhaust gas to preheat the water entering the water heater 100, thereby improving the heating efficiency of the water heater 100 and saving the gas consumption of the water heater 100, so that the water heater 100 can achieve a high energy efficiency level.

[0069] In the heat recovery component 30, the principle of phase equilibrium between gas and water vapor is utilized. If the temperature of the exhaust gas is not lower than its dew point temperature, condensation will not occur, thus preventing the generation of condensate. In the heat recovery component 30, a temperature and humidity detection module 35 acquires the temperature and humidity information of the high-temperature exhaust gas discharged from the water heater 100 and outputs it to the main control chip of the water heater 100. The main control chip calculates the dew point temperature of the exhaust gas based on the temperature and humidity information, and then controls the operation of the heat recovery component 30 according to the dew point temperature of the exhaust gas. This recovers the heat generated during the process of the high-temperature exhaust gas decreasing from its original temperature to its dew point temperature, and uses the recovered heat to preheat the inlet water of the water heater 100.

[0070] During the preheating stage of the water heater 100, the main control chip of the water heater 100 controls the speed of the circulating pump 34 through a 50% duty cycle PWM wave, so that the heat transfer medium flows. After the heat transfer medium flows, the heat of the high-temperature exhaust gas discharged by the water heater 100 will be absorbed by the heat recovery component 30. The absorbed heat is transferred to the heat recovery pipe 32 through the flowing heat transfer medium. After the heat of the high-temperature exhaust gas discharged by the water heater 100 is absorbed by the heat recovery pipe 32, the water inlet of the water heater 100 is preheated. During this process, the temperature of the high-temperature exhaust gas decreases and is controlled above the dew point temperature.

[0071] When the main control chip of the water heater 100 detects that the temperature of the exhaust gas is higher than the dew point temperature calculated by the main control chip, the main control chip gradually increases the duty cycle of the PWM wave of the circulation pump 34, thereby increasing the speed of the circulation pump 34 and improving the heat exchange on both sides of the insulation cylinder 33, thus rapidly preheating the water entering the water heater 100. If the main control chip detects that the temperature of the exhaust gas is lower than or equal to the dew point temperature calculated by the main control chip, the speed of the circulation pump 34 needs to be rapidly reduced to decrease the heat exchange on both sides of the insulation cylinder 33, so that the exhaust gas temperature can be maintained above the dew point temperature. At this time, no condensate will be produced in the exhaust gas, and the main control chip will control the circulation pump 34 to reduce the duty cycle of the PWM wave to the minimum, and the circulation pump 34 will operate at the lowest speed.

[0072] The system monitors again to determine if the exhaust gas temperature is higher than the dew point temperature calculated by the main control chip. If the exhaust gas temperature is lower than or equal to the dew point temperature, the output of the PWM wave to the circulation pump 34 is stopped. At this time, the circulation pump 34 stops running, the heat transfer medium stops flowing, and the heat insulation cylinder 33 blocks the transfer of heat between the two sides. The heat of the exhaust gas is not absorbed, the exhaust gas temperature will not drop, and the exhaust gas temperature will not fall below the dew point temperature. Condensation will not occur inside the water heater 100. If the exhaust gas temperature is higher than the dew point temperature, the duty cycle of the PWM wave is gradually increased, and the speed of the circulation pump 34 is increased until the most suitable speed of the circulation pump 34 is found.

[0073] Thirdly, the present invention provides a readable storage medium storing computer instructions, which, when executed, implement the control method of the water heater 100 described in the second aspect.

[0074] In this embodiment, the readable storage medium provided in this embodiment, by adopting the control method of the water heater 100 of the above-described embodiments, has all the technical effects of the control method of the water heater 100 described above. The specific technical effects of the computer-readable storage medium will not be elaborated here.

[0075] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A heat recovery device for a water heater, characterized in that, The heat recovery device includes: A flue pipe (20) has a flue chamber (21) inside for discharging exhaust gas from the water heater (100); A heat recovery assembly (30) is installed in the exhaust chamber (21). The heat recovery assembly (30) includes a heat exchange shell (31), a heat recovery pipe (32), and a heat transfer medium. A heat exchange chamber is formed inside the heat exchange shell (31). The heat recovery pipe (32) and the heat transfer medium are both installed in the heat exchange chamber. The heat recovery pipe (32) exchanges heat with the exhaust gas in the exhaust chamber (21) through the heat transfer medium. The heat recovery assembly (30) also includes a circulation pump (34), which is disposed in the heat exchange shell (31) and connected to the heat transfer medium. The circulation pump (34) controls the heat exchange efficiency between the heat recovery pipe (32) and the waste gas by controlling the circulation efficiency of the heat transfer medium.

2. The heat recovery device for a water heater according to claim 1, characterized in that, The heat exchange chamber is provided with a heat recovery tube chamber and a heat transfer medium chamber, and a circulation channel is provided between the heat recovery tube chamber and the heat transfer medium chamber, and the circulation pump (34) is located in the circulation channel.

3. The heat recovery device for a water heater according to claim 2, characterized in that, A heat exchange chamber is provided in the middle of the heat exchange chamber. The heat recovery tube chamber is formed inside the heat insulation cylinder (33). The heat transfer medium chamber is formed outside the heat insulation cylinder (33). A heat transfer medium inlet is provided at the bottom of the heat insulation cylinder (33). A heat transfer medium outlet is provided at the top of the heat insulation cylinder (33). A circulation pump (34) is provided at the heat transfer medium inlet and / or the heat transfer medium outlet.

4. The heat recovery device for a water heater according to claim 1, characterized in that, The heat recovery assembly (30) also includes a temperature and humidity detection module (35), which is disposed in the heat exchange shell (31) and located in the exhaust chamber (21) to detect the dew point temperature of the exhaust gas.

5. The heat recovery device for a water heater according to any one of claims 1 to 4, characterized in that, The heat recovery pipe (32) is connected in series to the water inlet pipe of the water heater (100) for preheating the water inlet of the water heater (100), and the heat recovery pipe (32) is provided with a flow section located in the heat exchange chamber and spiraling downward.

6. A method for controlling a water heater, characterized in that, The control method for the water heater (100) is implemented by the heat recovery device for the water heater (100) according to any one of claims 1 to 5, and the control method for the water heater (100) includes: Obtain the emission information of the exhaust gas; Obtain the operating status of the heat recovery pipe (32); Based on the exhaust gas emission information and the working status of the heat recovery pipe (32), the circulating pump (34) is controlled to drive the heat transfer medium to circulate or stop flowing.

7. The control method for a water heater according to claim 6, characterized in that, The step of controlling the circulation pump (34) to drive the heat transfer medium to circulate or stop flowing based on the exhaust gas emission information and the working status of the heat recovery pipe (32) specifically includes: Obtain the dew point temperature and real-time temperature of the exhaust gas; Compare the real-time temperature of the exhaust gas with the dew point temperature; Based on the real-time temperature being greater than the dew point temperature, the circulation efficiency of the heat transfer medium is controlled by the circulation pump (34), and the heat exchange efficiency between the heat recovery pipe (32) and the waste gas is controlled. If the real-time temperature is less than or equal to the dew point temperature, the circulation of the heat transfer medium is stopped by the circulation pump (34) until the real-time temperature is greater than the dew point temperature.

8. The control method for a water heater according to claim 7, characterized in that, The specific steps of obtaining the dew point temperature of the exhaust gas include: The real-time temperature and humidity of the exhaust gas are obtained; The dew point temperature of the exhaust gas is calculated based on the real-time temperature and the real-time humidity. The saturated vapor pressure es is calculated using the real-time temperature T, the actual vapor pressure e is calculated using the humidity RH, and the dew point temperature Td is calculated using the actual vapor pressure e.

9. The control method for a water heater according to claim 7, characterized in that, The step of controlling the circulation pump (34) to drive the heat transfer medium to circulate or stop flowing based on the exhaust gas emission information and the working status of the heat recovery pipe (32) further includes: Obtain the required water temperature for the heat recovery pipe (32); Calculate the temperature difference between the real-time temperature and the dew point temperature; The power of the circulating pump (34) is controlled according to the required water temperature and the temperature difference.

10. A readable storage medium, characterized in that, The readable storage medium stores computer instructions that, when executed, implement the control method of the water heater (100) according to any one of claims 6 to 9.

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