CN101839543B - Liquid heating device with low power consumption, control method and manufacturing method of the device - Google Patents

Abstract

The invention relates to a liquid heating device with low power consumption, a control method and a manufacturing method thereof. Comprises a core assembly for heating the liquid; the core assembly is provided with a water inlet level, a water outlet level and a channel, and the channel is connected with the water inlet level and the water outlet level; the core assembly is provided with a heating component; the heating component comprises a resistance element with a Europe unit as a unit, and the resistance value is less than 31 and more than 10; the electric power of the heat generating component is determined according to the voltage supplied by the power grid in watt; a ratio of electrical power of the heat generating component to a surface area of the heat generating component in square centimeters is less than 33 and greater than 14; a heat diffusion part is arranged in the core assembly, the heat diffusion part is a plane part, one surface of the heat diffusion part is in direct contact with the channel, and the other surface of the heat diffusion part is attached to the heating component; a heating control device for controlling the heating component by duty ratio; the duty ratio is the ratio of the time of starting the heating component in a period of 1 second according to different liquid input temperatures.

Description

Liquid heating device with low power consumption, control method and manufacturing method of the device

technical field

The present invention relates to a liquid heating device with low power consumption, a control method and a manufacturing method of the device, especially a liquid heating device for an automatic water dispenser or a beverage diverter, such as some well-known coffee machines or Water heaters and other devices.

technical background

There are different liquid heating devices on the market, such as hot water or beverage diverters. Each liquid heating device has different designs to meet the needs of different users. For example, one of the basic needs is a commercial drinking water heater for hotels. This application requires that a large amount of hot water can be provided to multiple hotel rooms at the same time without hindrance. Based on this demand, the liquid heater in the hotel is usually equipped with a water storage tank to store and maintain a relatively large amount of hot water to meet the consumption of hotel guests, so supplying hot water to meet the needs of multiple guests is a priority. In addition, the supply of hot water with high temperature (such as greater than 50°C) is second. Another basic use of hotel hot water is for bathing, so hot water with too high temperature is not needed. Furthermore, the requirements for real-time extraction of hot water in hotel rooms are not high.

Because user expectations vary. For example, a user drawing hot water from a hot water diverter would expect that the water discharged from the diverter will be hotter, and preferably achievable at a temperature of 95°C to 100°C. Users also expect that the liquid diverter can discharge hot water in real time or within a very short period of time, such as less than 10 seconds. In addition, the drinking water diverter is expected to operate efficiently while utilizing a minimum of energy in operation, and it is even desirable that the diverter be relatively durable. Unfortunately, common liquid splitters often have one or another problem that cannot be fully resolved.

When all countries in the world start to pay attention to environmental pollution and energy conservation, and everyone is talking about reducing carbon emissions, energy conservation and manufacturing products with low power consumption can be given priority. Some hot water heaters on the market use relatively high power consumption (such as 2600W), and the hot water produced is about 80°C to 90°C. Although hot water can be generated in a relatively short period of time, the consumed Power consumption is still relatively high.

Common hot water supply devices in the market generally lead the water source into the heating unit, and the water source flows from the bottom of the heating unit to the top of the heating unit for circulation. During the circulation process, the water source directly contacts the heating unit (such as a heating resistor) to heat. In this case, the initial water supply in the heating unit is heated too quickly, and a portion of the heated water supply will phase change into steam and rise to the upper half of the heating unit, while the water supply remaining in liquid form is still heated the lower half of the unit, resulting in a temperature increase in the upper half than in the lower half. When this happens, due to the difference in heat, each part of the heating unit will bear a huge and uneven heat pressure, and cracks will easily form after a long period of use. When cracks are formed in the heating unit, the heating components of the unit will inevitably be affected, and even easily destroyed. In addition, the circuit is usually located on the other side of the heating unit, and a crack in the heating unit will also destroy the heating resistor circuit. Likewise, in common liquid heaters, when no or insufficient water is sourced into the heating unit, the heating element is easily overheated and destroyed. To solve this problem, some common hot water supply devices usually have a complex electronic temperature control to monitor and limit the maximum heating temperature. However, these circuits often fail to solve the problem adequately and often create other new problems. Among other things, these circuits are very expensive and need to be added to the production cost.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a low power consumption liquid heating device with fast heating speed but lower power and longer service life. That is, the purpose of the present invention is to produce the effect of low power consumption under the premise of short heating time and reaching a certain temperature value.

Another technical problem to be solved by the present invention is to provide a control method for a liquid heating device that realizes low power consumption.

Another technical problem to be solved by the present invention is to provide a method for manufacturing a liquid heating device that realizes low power consumption.

The specific technical scheme is as follows:

A low power consumption liquid heating apparatus comprising:

(a) a core assembly for heating a liquid;

The core assembly is provided with a water inlet level, a water outlet level and a channel, and the channel connects the water inlet level and the water outlet level;

The core assembly is provided with a heating component; the heating component includes a resistance element in ohms, the resistance value is less than 31 and greater than 10; the electric power of the heating component is determined in watts according to the voltage supplied by the grid; The ratio of the electric power of the heating component to the surface area of the heating component in square centimeters is less than 33 and greater than 14;

The core assembly is provided with a thermal diffusion part, the thermal diffusion part is a planar part, and one side directly contacts the channel, and the other side is attached to the heating component;

(c) The heating control device that controls the heating component through the duty cycle; the duty cycle is the ratio of the time that the heating component is turned on in a period of 1 second according to different liquid input temperatures.

When the grid voltage is 100V to 120V, the electric power of the heating device is 1000 watts to 1500 watts, and the liquid flow rate of the heating device is 200 milliliters per minute to 350 milliliters per minute.

When the grid voltage is 210V to 240V, the electric power of the heating device is 1800 watts to 2500 watts, and the liquid flow rate of the heating device is 400 milliliters per minute to 550 milliliters per minute.

The water inlet level is connected with a conveying device, which is a water pump, an air pump or a water conveying device integrated with a core component.

A temperature sensor is provided on the surface of the heating component, and the heating control device detects the surface temperature of the heating component through the temperature sensor.

The ratio of the electric power to the surface area of the heating component is less than 23 and greater than 14.

The surface of the heating component is provided with a thermostatic switch.

The input temperature of the liquid is greater than 10°C.

The channels within the core assembly are arranged relatively long and convoluted within the core.

The arrangement direction of the main part of the channel is parallel to the direction of the water inlet level or the water outlet level.

The invention also discloses a control method of a liquid heating device, which is characterized in that: when the main power is turned on, the system is in a standby state and detects whether there is a trigger button; when the button is triggered, the temperature sensor on the surface of the heating component will Send the current surface temperature HST back to the control component. When the surface temperature is higher than 50°C, the system will be in the ready state in real time; When it is in the ready state, the system will detect whether the button is triggered again. When the button is triggered again and the pressing time is less than 2 seconds, the system will execute the procedure of rated flow output. When the button is triggered again and kept pressed for more than 2 seconds, the system executes the procedure of outputting flow on demand.

Wherein, the rated flow output program includes the following steps:

A: Start the button and the duration is less than the set value, the water pump and heating components will start;

B: The heating component automatically selects the corresponding duty cycle according to the input liquid temperature;

C: The temperature sensor on the surface of the heating component obtains the surface temperature of the heating component; if the surface temperature is not greater than 100°C, start the heating component at a duty cycle and enter step D; if the surface temperature is greater than 100°C, proceed to step E;

D: Detect whether the specified output water flow reaches the rated value, if it reaches the rated value, enter step E; if not, return to step B;

E: Turn off the water pump and heating components.

Wherein, the procedure for outputting traffic on demand includes the following steps:

A: Start the button and the duration is greater than the set value, the water pump and heating components will start;

B: The heating component automatically selects the corresponding duty cycle according to the input liquid temperature;

C: The temperature sensor on the surface of the heating component obtains the surface temperature of the heating component; if the surface temperature is not greater than 100°C, start the heating component at a duty cycle and enter step D; if the surface temperature is greater than 100°C, proceed to step E;

D: Detect whether the button has been released, if it is released, go to step E; if it is not released, return to step B;

E: Turn off the water pump and heating components.

The present invention further discloses a manufacturing method of a liquid heating device, which is characterized by comprising the following steps: preparing a core with a water inlet level and a water outlet level; arranging at least one heat diffusion component on one side of the core, and using the inner wall of the core and The thermal diffusion part is used to form a channel communicating with the water inlet level and the water outlet level; the other side of the thermal diffusion part is provided with a heating component; the core, the thermal diffusion part and the heating component form a core assembly; a shell is arranged outside the core assembly to strengthen The overall structure of the liquid heating device.

The method may also include the step of attaching two of the above-mentioned heat spreading members and sandwiching the core by these two heat spreading members.

The method may also include the step of connecting the inlet level of the core to a liquid transfer device in any manner.

The method may further include the step of configuring a heating control device, the heating assembly executing a program set by the heating control device when heating.

The present invention attaches a heat diffusion member or a heat spreader between the core and the heat generating component, and simultaneously sets the ratio of the electric power of the heat generating component to the surface area of the heat generating component and the duty cycle of the heating control device. Therefore, the liquid heating device of the present invention has multiple technical and functional advantages. First, heat spreading components reduce the risk of overheating heat-generating components. Since the heat energy generated from the heating component will not be directly transmitted to the core, instead the heat of the heating component will first spread to the thermal diffusion part under controllable conditions, and the liquid in the core can be evenly heated. Second, the heat spreader actually acts as a heat capacity and acts as a thermal resistance when heating the core. When the water source is introduced into the core to heat, the heat source is directly extracted from the thermal diffusion part instead of the prior art directly from the heating component, and when there is not enough liquid in the core, the function of the thermal diffusion part can protect the heating component from overheating. Third, based on the existence of the thermal diffusion component, the core can be heated evenly, thereby reducing the amount of vaporized liquid, so that the heated liquid can be discharged more smoothly. Fourth, the existence of thermal diffusion components can be used as a barrier between the heat-generating components and the core, but since the thermal diffusion components have a higher heat transfer coefficient than the heat-generating components, the thermal diffusion components not only do not hinder the heat source from the heating components to the core , and facilitates liquid heating by using heat spreading components to increase the heat transfer rate from the heat generating element to the liquid in the core. On the basis of the above, the ratio of the electric power of the heating element to the surface area of the heating element and the duty cycle of the heating control device are set. The effect of fast heating speed but lower power can be obtained, that is, the heating time shortened or the heating power reduced by the present invention. Compared with the prior art, the effect is produced under the premise of low power consumption and a certain same temperature value.

Description of drawings

The specific implementation of the present invention will now be described through the following examples and accompanying drawings.

FIG. 1 is a perspective view of a core assembly in a liquid heating device in Embodiment 1. FIG.

FIG. 2 is an exploded view of the core assembly in the liquid heating device of FIG. 1. FIG.

Fig. 3 is a perspective view of the inner core assembly of the liquid heating device in embodiment 2.

FIG. 4 is an exploded view of the core assembly in the liquid heating device of FIG. 3 .

Fig. 5 is a perspective view of the inner core assembly of the liquid heating device in the third embodiment.

Figure 6 is an exploded view of the core assembly in the liquid heating device of Figure 5 .

Fig. 7 is another assembly method of the inner core assembly of the liquid heating device in embodiment 3.

Figure 8 is a data flow diagram of the liquid heating device.

Fig. 9 is a flow chart of a rated hot water output control program.

Fig. 10 is a flow chart of a control program for outputting hot water according to demand.

Fig. 11 is a flow chart of controlling the heating cycle of the heating components in the liquid heating device.

Detailed ways

Example 1:

Accompanying drawings 1 to 2 are a specific embodiment of the inner core assembly 9 of a liquid heating device (such as a drinking water heating device). The core 92 shown in this embodiment is integrally manufactured with the heat diffusion components 64 on both sides and the channel. The core 92 is essentially extruded from aluminum, such as an aluminum alloy, and the two ends are connected by cover plates to form the core as a whole, as shown in Figure 1 and Figure 2 . After the core 92 is formed, two heat-generating components 96 are disposed opposite to the two surfaces of the core 92 and sandwich the core. After the two heating components 96 have been configured, the two bracket components 90 and the corresponding pressing blocks are relatively arranged on the other surface of the heating component 96. The bracket component 90 provides a pressure perpendicular to the core assembly 9 to make the heating component 96 is close to the core 92. The bracket assembly 90 can be made of aluminum, synthetic resin (bakelite) or silicone. After the core assembly is formed, other devices, such as liquid delivery devices, can be connected to form a complete liquid heating device.

According to this embodiment, after the configuration of the core 92 is completed, the junction 11 between the water inlet 6 and the water outlet 10 can be used to connect other devices. When the liquid enters the core 92 through the junction 11, the core 92 provides a "U" shape combination. The liquid flow path through which the liquid passes to be heated. After heating component 96 turns on power supply, heating component 96 heats thermal diffusion component 64 at first, because thermal diffusion component 64 is aluminum, its heat capacity and heat transfer coefficient are relatively high, after thermal diffusion component 64 is heated, heat Then quickly spread to the entire surface, when the liquid flows through the surface of the thermal diffusion component 64, the liquid will be heated evenly, and due to the high heat capacity and heat transfer coefficient of aluminum, the heat pressure will be evenly distributed on the entire surface, and There will be no overstressing, thereby protecting the core 92 and the heat-generating components 96 from damage.

With the above structure, the power used by the heating components can also be reduced. For example, the power grid in the United States is 110V. Compared with the existing liquid heating device, the electric power consumed under the same conditions is about 1300W, and the power grid in Europe is about 220V. , compared with the existing liquid heating device, the electric power consumed under the same conditions is 2200W. The core assembly in this liquid device reduces power consumption compared to other products.

Example 2

Figures 3 to 4 show another specific embodiment of the inner core assembly of the liquid heating device. As shown in FIG. 3 , the liquid heating device inner core assembly is generally indicated at 4 . The inner core assembly 4 of the liquid heating device is provided with an inlet 6 , an outlet 10 and two joints 11 .

Figure 4 is an exploded view of the inner core assembly of the liquid heating device in Figure 3 . The liquid heating core assembly 4 includes a core base assembly 4a in the middle of the assembly. Two sides of the core base assembly 4a respectively provide a space for accommodating the channel 4b and the channel 4c.

In this embodiment, the core assembly 4 is different from the embodiment 1. The core assembly of embodiment 1 is manufactured by integrating the channel and the thermal diffusion part. However, in Embodiment 2, the core assembly 4 is respectively configured as a core base assembly 4a, a channel 4b and a channel 4c. The core base 4a, the channel 4b and the channel 4c can be made of cast aluminum respectively, and other metal materials such as stainless steel or other non-toxic, heat-resistant non-metallic materials containing food signs such as Teflon, synthetic resin (bakelite) can also be used , Ceramic, Nylon or Silicone. After the channel 4b and the channel 4c are arranged on the core base 4a, two thermal diffusion parts 23 are respectively covered on the surface of the channel 4c and the channel 4c, and the thermal diffusion part 23 is directly in contact with the channel 4b and the channel 4c to form a liquid flow channel The heat diffusion member 23 is made of aluminum. A pair of heating components 33 are respectively covered on the other surface of the thermal diffusion part 23, a pair of pressure rings 82a are respectively covered on the surface of the thermal diffusion part 23, and a pair of bracket components 91 in the drawings are similar to Embodiment 1 and embedded in the The entire assembly to provide a pressure perpendicular to the core assembly.

Similar to Embodiment 1, after the configuration of the core assembly 4 is completed, it can be connected to other equipment to form a complete liquid heating device. The difference between Embodiment 2 and Embodiment 1 is that the core base 4a divides the channel into two parts. When the liquid enters from the junction 11, the liquid will first enter the first channel 4b for heating, and then enter the second channel 4b. Each channel 4c is reheated, because the heating time is prolonged, which can ensure that the liquid has enough time to heat up in the core assembly. In addition, because of this, the power used by heating components can also be reduced. For example, the power grid in the United States is 110V. Compared with the existing liquid heating device, the electric power consumed under the same conditions is about 1300W, and the power grid in Europe is about 220V. Compared with the existing liquid heating device, the electric power consumed under the same conditions is 2200W. The core assembly in this liquid device reduces power consumption compared to other products.

Example 3

Figures 5 to 6 show another embodiment of the inner core assembly of the liquid heating device. As shown in Figure 5, the liquid heating unit inner core assembly is generally indicated at 2. Two joints 11 are attached to the top of the core part 2a in this liquid heating device.

Fig. 6 is an exploded view of the main components of the core components in the liquid heating device. The core assembly 2 of the liquid heating device comprises a core part 2 a in the middle part of the device 2 . The core part 2a provides a liquid inlet level 6 through which liquid is introduced into the core part 2a. The core part 2a also provides a liquid outlet level 10 through which the heated liquid leaves the core part 2a. A thermal diffusion component 24 covers the core component 2 a to form a channel, a heating element 32 is attached to the other surface of the thermal diffusion component 24 , a pressure ring 36 and a base 38 form a protective cover to protect the core assembly 2 . A brace that provides pressure perpendicular to the core assembly is omitted here.

In this embodiment, the core part 2a provides a front side and a back side. The core part 2a provides a serpentine channel 21 on the front part, and two openings are respectively arranged at the two ends of the channel to connect to the water inlet level and the water outlet level. In this embodiment, the core component 2a is made of cast aluminum, and other metal materials such as stainless steel or other non-toxic, heat-resistant non-metal materials containing food signs such as Teflon, synthetic resin (bakelite), ceramics can also be used Or made of nylon or silicone.

Figure 7 discloses other configurations of the core part 2a in the liquid heating device. This figure shows an exploded view of the series connection. In different applications, they can be connected in parallel: as shown in the embodiment, each group is an independent component, and each independent component is connected by the water inlet level and the water outlet level, so that the heating device can be used more effectively.

Similar to Embodiment 1 and Embodiment 2, after the configuration of the core component is completed, the core assembly 2 can be connected with other devices to form a complete liquid heating device.

With the above structure, the power used by the heating components can also be reduced. For example, the power grid in the United States is 110V. Compared with the existing liquid heating device, the electric power consumed under the same conditions is about 1300W, and the power grid in Europe is about 220V. , compared with the existing liquid heating device, the electric power consumed under the same conditions is 2200W. The core assembly in this liquid device reduces power consumption compared to other products.

Through experimental tests, the liquid heating device of the present invention can discharge hot water satisfactorily. The following table summarizes the experimental conditions and experimental results.

The above experiments were performed without executing the program. According to the experimental results, in the case of a fixed heating power, if the temperature of the water output is to reach 95°C under different water inlet temperatures, the flow rate of the water will be different.

Accompanying drawing 8 to accompanying drawing 11 are the flowcharts of the electronic control part of the liquid heating device of the present invention. HST in the figure represents the surface temperature of the heating element, and IWT represents the temperature of the input water; the following procedures can be applied in each of the above-mentioned embodiments. According to the present invention, a temperature sensor (NTC) is arranged on the surface of the first group (that is, the group that first exchanges heat with the liquid) in the core assembly, and another thermostat switch (Thermostat) is also arranged on the core assembly at the same time On the surface of the first group of heat-generating components in the part. The temperature sensor is used to detect the surface temperature of the heating component, and the heating program of the liquid heating device is determined according to the signal fed back by the temperature sensor.

Under normal circumstances, the temperature sensor (NTC) will be responsible for detecting the surface temperature of the heating component. When there is not enough liquid in the core assembly for heating, the temperature sensor will send a signal to the control component and stop all operations. A temperature sensor (NTC) acts as a first layer of protection in case of overheating and dry burn.

When the electronic control fails, another temperature detection device, the thermostat switch, will function. This thermostat switch is a mechanical temperature inspection device. When the surface temperature of the heating component is too high or dry burning occurs, and the electronic temperature sensor fails, when the surface temperature of the heating component is higher than the default value of the thermostat switch, the thermostat switch will cut off all power supplies to protect the entire Liquid heating device. This thermostatic switch acts as a second layer of protection in case of overheating and dry burn.

Accompanying drawing 8 is the data flow chart of the dry burning protection program contained in the liquid heating device. According to this flow chart, when the main power is turned on, the system will first be in the standby state and detect whether there is a trigger button. When the button is triggered, the temperature sensor on the surface of the heating component will send the current surface temperature HST back to the control component. When the surface temperature is higher than 50°C, the system will be ready in real time. When the surface temperature is lower than 50°C, the heating element will be turned on for 2 seconds before turning to the ready state.

When the system is in the ready state, the system will detect whether the button is triggered again. When the button is triggered again and the pressing time is less than 2 seconds, the system will execute the procedure of rated flow output. When the button is triggered again and kept pressed for more than 2 seconds, the system will execute the output program on demand.

Accompanying drawing 9 is the flow chart of the rated hot water output program including dry heating protection. According to the program, when the button is triggered for the second time and the pressing time is less than 2 seconds, the system will execute this program. The entire cycle of this program is 1 second. The duty cycle mentioned in the flowchart refers to the time that the heating element is turned on within a 1-second cycle, which is determined according to the temperature of the liquid entering. At the same time, the temperature sensor on the surface of the heating element detects the surface temperature of the heating element. This procedure is used to detect whether dry burning occurs. Under normal circumstances, after the system outputs the rated flow, all devices are turned off, and the system returns to its original state.

Accompanying drawing 10 is the flow chart of outputting water volume program according to demand including dry heating protection. According to the program, when the button is triggered for the second time and kept pressed for more than 2 seconds, the system will execute this program. Similar to the program described in Figure 9, the entire cycle of this program is 1 second, and the duty cycle described in the flowchart refers to the time that the heating element is turned on within a 1-second cycle, which is determined according to the temperature of the liquid entering Decide. At the same time, the temperature sensor on the surface of the heating element detects the surface temperature of the heating element. This procedure is used to detect whether dry burning occurs. Under normal circumstances, as long as there is sufficient water supply and the user keeps pressing the button, the system will continue to operate until overheating or dry boiling occurs.

Accompanying drawing 11 is the flow chart of determining the control heating period of the heating element in the liquid heating device. According to this flowchart, the heating cycle of the heating element will be determined according to the temperature of the liquid entering. Each cycle in the flow chart is 1 second. If the temperature of the liquid entering is less than 15°C, the duty cycle of 100% in the flow chart means that the heating element is fully turned on 100% within a 1 second cycle. When the temperature of the liquid entering is between 15°C and 20°C, the 90% duty cycle in the flow chart means that the heating element is turned on for 90% of the time within a period of 1 second, and is turned off for the other 10% of the time.

In order to realize the premise of simple structure and simplified control, the control program of the present invention is applied. The control procedure of the present invention is aimed at determining the heating cycle according to different input temperatures under the premise of a fixed flow rate and an output temperature of 95°C. The present invention is equipped with the application of thermal diffusion components and two-stage heating, and the output temperature can be fixed between 92°C and 96°C. Also because of this, the situation of gasification can also be greatly reduced, and the output water flow can also be output smoothly.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the patent of the present invention. Therefore, any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims (17)

1. A liquid heating device with low power consumption, comprising: core assembly for heating the liquid; The core assembly is provided with a water inlet level, a water outlet level and a channel, and the channel connects the water inlet level and the water outlet level; The core assembly is provided with a heating component; the heating component includes a resistance element in ohms, the resistance value is less than 31 and greater than 10; the electric power of the heating component is determined in watts according to the voltage supplied by the grid; The ratio of the electric power of the heating component to the surface area of the heating component in square centimeters is less than 33 and greater than 14; The core assembly is provided with a thermal diffusion part, the thermal diffusion part is a planar part, and one side directly contacts the channel, and the other side is attached to the heating component; The heating control device of the heating component is controlled by the duty cycle; the duty cycle is the ratio of the time of turning on the heating component in a period of 1 second according to different liquid input temperatures. 2. The liquid heating device according to claim 1, characterized in that: when the grid voltage is 100V to 120V, the electric power of the heating device is 1000 watts to 1800 watts, and the liquid flow rate of the heating device is 200 milliliters per minute to 200 milliliters per minute 350ml. 3. The liquid heating device according to claim 1, characterized in that: when the grid voltage is 210V to 240V, the electric power of the heating device is 1800 watts to 2500 watts, and the liquid flow rate of the heating device is 400 milliliters per minute to 400 milliliters per minute. Min 550 ml. 4. The liquid heating device according to claim 1, wherein the water inlet level is connected to a conveying device, and the conveying device is a water pump, an air pump or a water conveying device integrated with a core assembly. 5. The liquid heating device according to claim 1, wherein a temperature sensor is provided on the surface of the heating component, and the heating control device detects the surface temperature of the heating component through the temperature sensor. 6. The liquid heating device according to claim 1, wherein the ratio of the electric power to the surface area of the heating element is less than 24 and greater than 14. 7. The liquid heating device according to claim 1, wherein a thermostatic switch is provided on the surface of the heating component. 8. The liquid heating device according to claim 1, wherein the input temperature of the liquid is greater than 10°C. 9. A liquid heating device as claimed in any one of claims 1 to 8, characterized in that the channels in the core assembly are arranged to be relatively long and convolute within the core. 10. The liquid heating device according to claim 9, characterized in that: the arrangement direction of the main part of the channel is parallel to the direction of the water inlet level or the water outlet level. 11. The control method of the liquid heating device according to any one of claims 1-10, characterized in that: when the main power is turned on, the system is first in a standby state and detects whether there is a trigger button; when the button is triggered, the heating element The temperature sensor on the surface sends the surface temperature HST back to the control component. When the surface temperature is higher than 50°C, the system will be ready in real time; when the surface temperature is lower than 50°C, the heating component will be turned on after 2 seconds Then turn to the ready state; when the system is in the ready state, the system will detect whether the button is triggered again, when the button is triggered again and the pressing time is less than 2 seconds, the system will execute the procedure of rated flow output; when the button is in When it is triggered again and kept pressed for more than 2 seconds, the system executes the program of outputting flow according to demand. 12. The control method of the liquid heating device according to claim 11, characterized in that: the rated flow output program comprises the following steps: A: Start the button and the duration is less than the set value, the water pump and heating components will start; B: The heating component automatically selects the corresponding duty cycle according to the input liquid temperature; C: The temperature sensor on the surface of the heating component obtains the surface temperature of the heating component; if the surface temperature is not greater than 100°C, start the heating component with a duty cycle and enter step D; if the surface temperature is greater than 100°C, enter step E; D: Detect whether the specified output water flow reaches the rated value, if it reaches the rated value, enter step E; if not, return to step B; E: Turn off the water pump and heating components. 13. The control method of the liquid heating device according to claim 11, characterized in that the program of outputting flow according to demand comprises the following steps: A: Start the button and the duration is greater than the set value, the water pump and heating components will start; B: The heating component automatically selects the corresponding duty cycle according to the input liquid temperature; C: The temperature sensor on the surface of the heating component obtains the surface temperature of the heating component; if the surface temperature is not greater than 100°C, start the heating component with a duty cycle and enter step D; if the surface temperature is greater than 100°C, enter step E; D: Detect whether the button has been released, if it is released, go to step E; if it is not released, return to step B; E: Turn off the water pump and heating components. 14. A method for manufacturing a liquid heating device according to any one of claims 1 to 10, characterized by comprising the following steps: preparing a core with a water inlet level and a water outlet level; arranging at least one thermal diffusion component on one side of the core , and the inner wall of the core and the thermal diffusion part are used to form a channel communicating with the water inlet level and the water outlet level; a heating component is arranged on the other side of the thermal diffusion part; the core, the thermal diffusion part and the heating component form a core assembly; a shell is set on the outside the core assembly to reinforce the overall structure of the liquid heating device. 15. The manufacturing method of the liquid heating device according to claim 14, characterized in that it includes the steps of attaching two heat diffusion parts and sandwiching the core between the two heat diffusion parts. 16. The manufacturing method of the liquid heating device according to claim 14, characterized in that it includes the step of connecting the water inlet level of the core to the liquid delivery device in any way. 17. The manufacturing method of the liquid heating device according to claim 14, characterized in that it includes the step of configuring a heating control device, and the heating component executes a program set by the heating control device when heating.