Water heater and heating method thereof

Abstract

The water heater comprises an inner container and a heat exchange assembly, water flows out of the upper portion of the inner container, water flows in of the lower portion of the inner container, and the heat exchange assembly comprises a first heat exchange flow channel arranged on the upper portion of the inner container and a second heat exchange flow channel arranged on the lower portion of the inner container; the heating method comprises the steps that on the basis that the heating condition is met and the difference between the set temperature and the first water temperature in the upper portion of the inner container is smaller than the first preset temperature difference, a refrigerant is only conveyed to the second heat exchange runner to heat the lower portion of the inner container. The water heater is high in energy efficiency, and the temperature of water in the inner container is more uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical appliances, and more specifically, to a water heater and a heating method thereof. Background Art

[0002] At present, a heat pump water heater includes an inner tank and a microchannel heat exchange component. The microchannel heat exchange component is arranged on the outer side wall of the inner tank. When high-temperature refrigerant flows through the microchannel heat exchange component, it can heat the water in the inner tank. The refrigerant inlet of the microchannel heat exchange component is close to the top end of the inner tank, and the refrigerant outlet of the microchannel heat exchange component is close to the bottom end of the inner tank. In the microchannel heat exchange component, the refrigerant flows from top to bottom, which results in a higher water temperature in the top area of the inner tank and a lower water temperature in the bottom area of the inner tank. Also, since the height of the inner tank in the vertical direction is relatively large, for example, the height of the inner tank is usually more than 1 meter, this will further lead to a larger temperature difference between the upper and lower parts of the inner tank. And a larger temperature difference between the upper and lower parts of the inner tank will result in a large temperature difference between the front and back water temperatures when the inner tank discharges hot water outward, seriously affecting the user experience.

[0003] When the heat pump operates, the water in the upper part of the inner tank is heated first, and the heating speed of the water in the lower part of the inner tank is much slower. Moreover, after one heating cycle is completed and the machine stops, when a small amount of water is used and the heat pump restarts, there is still a large amount of hot water in the upper part of the inner tank. When heating, not only the efficiency of the heat pump will be significantly reduced and the energy efficiency is low, but also the water temperature in the upper part of the inner tank will further increase, and the heating speed of the bottom of the inner tank is still very slow. Summary of the Invention

[0004] The present application provides a heating method for a water heater. The water heater includes an inner tank with upper water outlet and lower water inlet, and a heat exchange component. The heat exchange component includes a first heat exchange flow channel arranged in the upper part of the inner tank and a second heat exchange flow channel arranged in the lower part of the inner tank.

[0005] The heating method includes:

[0006] Based on reaching the heating condition and the difference between the set temperature and the first water temperature in the upper part of the inner tank being less than the first preset temperature difference, only supply refrigerant to the second heat exchange flow channel to heat the lower part of the inner tank.

[0007] In an exemplary embodiment, based on reaching the heating condition and the difference between the set temperature and the first water temperature in the upper part of the inner tank being greater than or equal to the first preset temperature difference, supply refrigerant to the first heat exchange flow channel and the second heat exchange flow channel simultaneously to heat the upper and lower parts of the inner tank simultaneously.

[0008] In an exemplary embodiment, when supplying refrigerant to the first heat exchange flow channel and the second heat exchange flow channel to heat the upper and lower parts of the inner tank simultaneously, the refrigerant flow rate in the second heat exchange flow channel is greater than the refrigerant flow rate in the first heat exchange flow channel.

[0009] In a schematic embodiment, delivering refrigerant to the first heat exchange channel and the second heat exchange channel to heat the upper and lower parts of the inner tank simultaneously includes:

[0010] Based on the difference between the first water temperature and the second water temperature in the lower part of the inner tank being greater than or equal to a second preset temperature difference, delivering refrigerant to the first heat exchange channel at a first refrigerant flow rate and delivering refrigerant to the second heat exchange channel at a second refrigerant flow rate;

[0011] Based on the difference between the first water temperature and the second water temperature being less than the second preset temperature difference, delivering refrigerant to the first heat exchange channel at a third refrigerant flow rate and delivering refrigerant to the second heat exchange channel at a fourth refrigerant flow rate;

[0012] Wherein, the second refrigerant flow rate is greater than the fourth refrigerant flow rate, and the third refrigerant flow rate is greater than the first refrigerant flow rate.

[0013] In a schematic embodiment, it further includes steps after delivering refrigerant to the first heat exchange channel and the second heat exchange channel:

[0014] Adjusting the refrigerant flow rate of the first heat exchange channel based on the difference between the first water temperature and the second water temperature in the lower part of the inner tank, and the refrigerant flow rate of the first heat exchange channel is positively correlated with the difference; and / or,

[0015] Adjusting the refrigerant flow rate of the second heat exchange channel based on the difference between the first water temperature and the second water temperature in the lower part of the inner tank, and the refrigerant flow rate of the second heat exchange channel is negatively correlated with the difference.

[0016] In a schematic embodiment, the water heater further includes a first valve provided on the pipeline between the outdoor unit and the first heat exchange channel and a second valve provided on the pipeline between the outdoor unit and the second heat exchange channel;

[0017] The heating method further includes: controlling the refrigerant flow rate of the first heat exchange channel by controlling the opening degree of the first valve, and controlling the refrigerant flow rate of the second heat exchange channel by controlling the opening degree of the second valve.

[0018] In a schematic embodiment, the heating condition is: the first water temperature in the upper part of the inner tank is less than the set temperature, or the second water temperature in the lower part of the inner tank is less than the sum of the set temperature and the preset temperature.

[0019] In a schematic embodiment, the heating method further includes:

[0020] Based on reaching the stop heating condition, stopping delivering refrigerant to the first heat exchange channel and the second heat exchange channel.

[0021] In a schematic embodiment, the heating stop condition is that the first water temperature is greater than the set temperature, or the second water temperature in the lower part of the inner tank is greater than the set temperature.

[0022] This application also provides a water heater, which includes:

[0023] An inner tank;

[0024] A heat exchange component, including a first heat exchange flow channel arranged in the upper part of the inner tank and a second heat exchange flow channel arranged in the lower part of the inner tank;

[0025] An external unit, which is connected to the first heat exchange flow channel and the second heat exchange flow channel through pipelines;

[0026] A first valve, which is arranged on the pipeline connecting the external unit and the first heat exchange flow channel;

[0027] A second valve, which is arranged on the pipeline connecting the external unit and the second heat exchange flow channel;

[0028] A first temperature sensor, which is used to detect the first water temperature in the upper part of the inner tank;

[0029] A second temperature sensor, which is used to detect the second water temperature in the lower part of the inner tank;

[0030] A controller, which is electrically connected to the first valve, the second valve, the external unit, the first temperature sensor and the second temperature sensor, and is configured to:

[0031] Based on reaching the heating condition and the difference between the set temperature and the first water temperature being less than the first preset temperature difference, close the first valve and open the second valve, and drive the external unit to only deliver refrigerant to the second heat exchange flow channel to heat the lower part of the inner tank.

[0032] When the user uses the hot water in the inner tank, the hot water in the inner tank is discharged from the upper part, and cold water is input into the inner tank 1 from the lower part of the inner tank. When the heating condition is reached, it usually indicates that the user is using hot water, and cold water is input from the lower part of the inner tank. When the difference between the set temperature and the first water temperature in the upper part of the inner tank is less than the first preset temperature difference, it indicates that the water level of the cold water input into the lower part of the inner tank has not reached the upper part of the inner tank. In this way, since there is still a large amount of hot water in the upper part of the inner tank, at this time, only the refrigerant is delivered to the second heat exchange flow channel to heat the relatively cold water in the lower part of the inner tank, which can accelerate the heating of the water temperature in the lower part of the inner tank, improve the heat exchange efficiency between the refrigerant and the water, and thus improve the energy efficiency of the water heater.

[0033] Other features and advantages of the present invention will be described in the subsequent specification, and some of them will become obvious from the specification, or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the specification and the drawings. Brief Description of the Drawings

[0034] The drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

[0035] Figure 1 It is a schematic structural diagram of a water heater in an embodiment of the present invention;

[0036] Figure 2 It is an unfolded schematic diagram of a heat exchange component in an embodiment of the present invention;

[0037] Figure 3 It is an unfolded schematic diagram of another heat exchange component in an embodiment of the present invention;

[0038] Figure 4 It is a flowchart of a heating method of a water heater in an embodiment of the present invention.

[0039] Reference Signs:

[0040] 1, inner tank; 11, cylinder body; 111, first end; 112, second end; 12, first end cover; 2, heat exchange component; 201, first refrigerant inlet; 202, second refrigerant inlet; 203, refrigerant outlet; 204, first heat exchange flow channel; 205, second heat exchange flow channel; 21, first header; 211, first pipe body; 2111, first pipe section; 2111a, first first pipe section; 2111b, second first pipe section; 2111c, third first pipe section; 212, first partition member; 22, second header; 221, second pipe body; 2211, second pipe section; 2211a, first second pipe section; 2211b, second second pipe section; 2211c, third second pipe section; 2211d, fourth second pipe section; 222, second partition member; 23, heat exchange pipe; 24, connecting member; 25, refrigerant interface assembly; 251, base; 252, input joint; 253, output joint; 26, input pipe assembly; 261, main pipeline; 262, tee fitting; 263, first branch pipe; 264, second branch pipe; 27, output pipe; 3, first temperature sensor; 4, second temperature sensor; 5, first valve; 6, second valve; 7, thermal insulation layer; 8, outer shell. Detailed Embodiments

[0041] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the embodiments of the present invention will be described in detail below with reference to the drawings. It should be noted that, without conflict, the embodiments and features in the present application can be combined with each other arbitrarily.

[0042] As Figure 1 shownFigure 1 Shows the structure of a water heater in this embodiment. The water heater can be an air source heat pump water heater. The water heater includes an inner tank 1, a heat exchange component 2, a first valve 5, a second valve 6, a temperature measuring component, an outdoor unit, and a controller. The outdoor unit and the heat exchange component 2 are connected through a refrigerant pipeline, and the outdoor unit can drive the refrigerant to circulate between the outdoor unit and the heat exchange component 2 to absorb heat from the air to heat the water stored in the heat exchange component 2.

[0043] The inner tank 1 has an inner cavity for storing water. The inner tank 1 includes a cylindrical body 11, a first end cover 12, and a second end cover. The cylindrical body 11 can be cylindrical. The cylindrical body 11 is formed by welding plates. The plates can be good conductors of heat, such as stainless steel plates or enameled steel plates. The cylindrical body 11 includes a first end 111 and a second end 112, and the first end 111 and the second end 112 are arranged oppositely. In this embodiment, the cylindrical body 11 is erected. The first end 111 of the cylindrical body 11 can be the upper end of the cylindrical body 11, and the second end 112 of the cylindrical body 11 can be the lower end. The first end cover 12 and the second end cover are configured as substantially disc-shaped structures. The first end cover covers the first end 111 of the cylindrical body 11 and seals the first end 111. The second end cover covers the second end 112 of the cylindrical body 11 and seals the second end 112. The first end cover and the second end cover can be welded to the cylindrical body 11, or can be screwed or riveted to the cylindrical body 11. The inner tank 1 is provided with a water inlet (not shown in the figure) and a water outlet (not shown in the figure). Both the water inlet and the water outlet communicate with the inner cavity of the inner tank 1. The water inlet is provided at the lower part of the inner tank 1, and the water outlet is provided at the upper part of the inner tank 1. The water inlet is used to inject water into the inner tank 1. The water outlet is used to discharge the water in the inner tank 1 from the inner tank 1. The water inlet can be provided at the second end 112 of the cylindrical body 11, and the water outlet can be provided at the first end 111 of the cylindrical body 11. The water inlet can be connected to the tap water supply pipeline, and the water outlet can be connected to the hot water use pipeline. When the user uses water, the water outlet of the inner tank 1 discharges hot water outwards, and the water inlet of the inner tank 1 injects cold water into the inner tank 1.

[0044] The heat exchange component 2 is arranged on the outer peripheral wall of the cylinder body 11. The heat exchange component 2 and the cylinder body 11 can be connected by screws, riveted or welded. The heat exchange component 2 is provided with a first heat exchange flow channel 204, a second heat exchange flow channel 205, a first refrigerant inlet 201, a second refrigerant inlet 202 and a refrigerant outlet 203. The first refrigerant inlet 201 is arranged outside the first end 111 of the cylinder body 11. The second refrigerant inlet 202 is arranged outside the second end 112 of the cylinder body 11. The refrigerant outlet 203 is arranged outside the middle part of the cylinder body 11. The first heat exchange flow channel 204 extends along the outer peripheral wall of the cylinder body 11, and the first heat exchange flow channel 204 extends meanderingly from the first refrigerant inlet 201 to the refrigerant outlet 203. The second heat exchange flow channel 205 extends along the outer peripheral wall of the cylinder body 11, and the second heat exchange flow channel 205 extends meanderingly from the second refrigerant inlet 202 to the refrigerant outlet 203. The first refrigerant inlet 201 and the refrigerant outlet 203 are respectively communicated with the opposite ends of the first heat exchange flow channel 204. The first refrigerant inlet 201 is used for injecting refrigerant into the first heat exchange flow channel 204. The second refrigerant inlet 202 and the refrigerant outlet 203 are respectively communicated with the opposite ends of the second heat exchange flow channel 205. The second refrigerant inlet 202 is used for injecting refrigerant into the second heat exchange flow channel 205. The refrigerant outlet 203 is used for discharging the refrigerant in the first heat exchange flow channel 204 from the first heat exchange flow channel 204 and discharging the refrigerant in the second heat exchange flow channel 205 from the second heat exchange flow channel 205.

[0045] The outdoor unit includes a refrigerant output port and a refrigerant return port. The refrigerant output port of the outdoor unit is connected to the first refrigerant inlet 201 of the heat exchange component 2 and the second refrigerant inlet 202 of the heat exchange component 2 through pipelines. The refrigerant output port of the outdoor unit can inject refrigerant into the first heat exchange flow channel 204 and the second heat exchange flow channel 205. The refrigerant return port is communicated with the refrigerant outlet 203 of the heat exchange component 2 through a pipeline. The refrigerant output from the first heat exchange flow channel 204 and the second heat exchange flow channel 205 can flow back to the outdoor unit through the refrigerant return port. The refrigerant output port of the outdoor unit can transport gaseous refrigerant to the first refrigerant inlet 201 and the second refrigerant inlet 202, and the temperature of this refrigerant is higher than the temperature of the water in the inner tank 1. When the gaseous refrigerant flows through the first heat exchange flow channel 204 and the second heat exchange flow channel 205, it transfers heat to the inner tank 1 to heat the water in the inner tank 1, and the gaseous refrigerant releases heat and is converted into liquid refrigerant. The liquid refrigerant is discharged from the refrigerant outlet 203 and flows back to the outdoor unit. When the refrigerant flows through the first heat exchange flow channel 204, the refrigerant heats the upper part of the inner tank 1. When the refrigerant flows through the second heat exchange flow channel 205, the refrigerant heats the lower part of the inner tank 1. The specific structure of the outdoor unit is the same as that of the outdoor unit of the existing heat pump water heater, and will not be elaborated here.

[0046] The first valve 5 can be an electronic expansion valve or a solenoid valve. The first valve 5 is disposed on the pipeline connecting the refrigerant outlet 203 of the outdoor unit and the first refrigerant inlet 201 of the heat exchange assembly 2. The refrigerant outlet 203 of the outdoor unit and the first refrigerant inlet 201 of the heat exchange assembly 2 are connected through the first valve 5. The first valve 5 can control the flow rate of the refrigerant flowing through the first heat exchange flow path 204.

[0047] The second valve 6 can be an electronic expansion valve or a solenoid valve. The second valve 6 is disposed on the pipeline connecting the refrigerant outlet 203 of the outdoor unit and the second refrigerant inlet 202 of the heat exchange assembly 2. The refrigerant outlet 203 of the outdoor unit and the second refrigerant inlet 202 of the heat exchange assembly 2 are connected through the second valve 6. The second valve 6 can control the flow rate of the refrigerant flowing through the second heat exchange flow path 205.

[0048] The temperature measuring assembly is used to measure the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1. In this embodiment, the temperature measuring assembly includes a first temperature sensor 3 and a second temperature sensor 4. The first temperature sensor 3 is disposed in the upper part of the inner tank 1 for measuring the first water temperature in the upper part of the inner tank 1. The second temperature sensor 4 is disposed in the lower part of the inner tank 1 for measuring the second water temperature in the lower part of the inner tank 1.

[0049] The controller is the logic control unit of the water heater. The controller can be a single-chip microcomputer. The controller is electrically connected to the first valve 5, the second valve 6, the outdoor unit, the first temperature sensor 3 and the second temperature sensor 4.

[0050] In this embodiment, as Figure 4 shown, a heating method for a water heater is also proposed. The heating method is implemented based on the above water heater. The heating method includes:

[0051] Step S1: The controller obtains the set temperature, the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1;

[0052] The set temperature is the temperature to be reached after the water in the inner tank 1 is heated. The set temperature can be set by the user, and the value range of the set temperature is usually 35-70 °C. The first water temperature in the upper part of the inner tank 1 is measured by the first temperature sensor 3. The second water temperature in the lower part of the inner tank 1 is measured by the second temperature sensor 4.

[0053] Step S2: The controller determines whether the heating condition is reached based on the set temperature, the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1. If so, go to step S3; otherwise, go to step S1;

[0054] The heating condition, under which the water in the inner tank 1 needs to be heated, can be determined according to the set temperature, the first water temperature, and the second water temperature. In this embodiment, the heating condition is that the first water temperature in the upper part of the inner tank 1 is lower than the set temperature, or the second water temperature in the lower part of the inner tank 1 is lower than the sum of the set temperature and the preset temperature.

[0055] When the first water temperature in the upper part of the inner tank 1 is lower than the set water temperature, it indicates that the water temperature in the inner tank 1 is already relatively low, and the water in the inner tank 1 needs to be heated.

[0056] When the second water temperature in the lower part of the inner tank 1 is lower than the sum of the set temperature and the preset temperature, it indicates that the water temperature in the inner tank 1 is already relatively low, and the water in the inner tank 1 needs to be heated. The value range of the preset temperature can be 20 - 40°C, preferably 30°C.

[0057] Step S3: The controller determines whether the difference between the set temperature and the first water temperature in the upper part of the inner tank 1 is less than the first preset temperature difference. If so, it proceeds to step S4;

[0058] The first preset temperature difference can be set relatively small. The first preset temperature difference can be 3 - 7°C, preferably 5°C.

[0059] Step S4: The controller closes the first valve 5, opens the second valve 6, and drives the external unit to deliver the refrigerant only to the second heat exchange flow path 205.

[0060] Control sets the opening degree of the first valve 5 to zero and the opening degree of the second valve 6 to 100%.

[0061] When the user uses the hot water in the inner tank 1, the hot water in the inner tank 1 is discharged from the upper part, and cold water is input into the inner tank 1 from the lower part of the inner tank 1. When the heating condition is reached, it usually indicates that the user is using hot water, and cold water is input from the lower part of the inner tank 1. When the difference between the set temperature and the first water temperature in the upper part of the inner tank 1 is less than the first preset temperature difference, it indicates that the water level of the cold water input from the lower part of the inner tank 1 has not reached the upper part of the inner tank 1. At this time, the controller closes the first valve 5 and opens the second valve 6. The first valve 5 cuts off the pipeline between the first heat exchange flow path 204 and the external unit, and the second valve 6 connects the pipeline between the second heat exchange flow path 205 and the external unit. The controller drives the external unit to deliver high-temperature and high-pressure refrigerant to the second heat exchange flow path 205 to only heat the lower part of the inner tank 1. In this way, since there is still a large amount of hot water in the upper part of the inner tank 1, at this time, only the refrigerant is delivered to the second heat exchange flow path 205 to heat the water with a lower temperature in the lower part of the inner tank 1, which can accelerate the heating of the water temperature in the lower part of the inner tank 1, improve the heat exchange efficiency between the refrigerant and the water, and thus improve the energy efficiency of the water heater.

[0062] In a schematic embodiment, the heating method further includes step S5.

[0063] In step S3, it also includes that when the difference between the set temperature and the first water temperature in the upper part of the inner tank 1 is greater than or equal to the first preset temperature difference, step S5 is entered;

[0064] Step S5: The controller controls both the first valve 5 and the second valve 6 to open, and the controller drives the external unit to simultaneously deliver refrigerant to the first heat exchange channel 204 and the second heat exchange channel 205.

[0065] When the heating condition is reached, it usually indicates that the user is using hot water, and cold water is input from the lower part of the inner tank 1. When the difference between the set temperature and the first water temperature in the upper part of the inner tank 1 is greater than or equal to the first preset temperature difference, it indicates that the water level of the cold water input from the lower part of the inner tank 1 has reached the upper part of the inner tank 1. At this time, the controller opens both the first valve 5 and the second valve 6. The first valve 5 connects the pipeline between the first heat exchange channel 204 and the external unit, and the second valve 6 connects the pipeline between the second heat exchange channel 205 and the external unit. The controller drives the external unit to deliver high-temperature and high-pressure refrigerant to the first heat exchange channel 204 and the second heat exchange channel 205 to simultaneously heat the upper and lower parts of the inner tank 1. In this way, since the water temperatures of the upper and lower parts of the inner tank 1 are both relatively low, delivering the refrigerant to the first heat exchange channel 204 and the second heat exchange channel 205 to simultaneously heat the upper and lower parts of the inner tank 1 at this time can simultaneously increase the water temperatures of the upper and lower parts of the inner tank 1, reduce the temperature difference in the inner tank 1, improve the heat exchange efficiency between the refrigerant and the water, and thus improve the energy efficiency of the water heater.

[0066] In a schematic embodiment, in step S5, the opening degree of the second valve 6 is greater than that of the first valve 5 so that the refrigerant flow rate in the second heat exchange channel 205 is greater than that in the first heat exchange channel 204.

[0067] By controlling the first valve 5 and the second valve 6 to respectively adjust the refrigerant flow rates in the first heat exchange channel 204 and the second heat exchange channel 205, so that the refrigerant flow rate in the second heat exchange channel 205 is greater than that in the first heat exchange channel. In this way, the heating power of the second heat exchange channel 205 for heating the lower part of the inner tank 1 is greater than the heating power of the first heat exchange channel 204 for heating the upper part of the inner tank 1. During the process of heating the inner tank 1, the rising speed of the water temperature in the lower part of the inner tank 1 is greater than that of the water temperature in the upper part of the inner tank 1, so as to reduce the water temperature difference between the upper and lower parts of the inner tank 1 and improve the energy efficiency level and user experience.

[0068] In a schematic embodiment, step S5 includes steps S51 to S53.

[0069] Step S51: The controller determines whether the difference between the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1 is greater than or equal to the second preset temperature difference. If so, step S52 is entered; otherwise, step S53 is entered;

[0070] The value range of the second preset temperature difference can be 6 - 14°C, and the second preset temperature difference is preferably 10°C.

[0071] Step S52: The controller controls the opening degrees of the first valve 5 and the second valve 6, so that the outdoor unit conveys the refrigerant to the first heat exchange channel 204 at the first refrigerant flow rate and conveys the refrigerant to the second heat exchange channel 205 at the second refrigerant flow rate.

[0072] The second refrigerant flow rate is greater than the first refrigerant flow rate. The opening degree of the first valve 5 can be 20%, and the opening degree of the second valve 6 can be 80%.

[0073] Step S53: The controller controls the opening degrees of the first valve 5 and the second valve 6, so that the outdoor unit conveys the refrigerant to the first heat exchange channel 204 at the third refrigerant flow rate and conveys the refrigerant to the second heat exchange channel 205 at the fourth refrigerant flow rate.

[0074] The third refrigerant flow rate is greater than the fourth refrigerant flow rate. The second refrigerant flow rate is greater than the fourth refrigerant flow rate, and the third refrigerant flow rate is greater than the first refrigerant flow rate. The opening degree of the first valve 5 can be 40%, and the opening degree of the second valve 6 can be 60%.

[0075] When the difference between the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1 is greater than or equal to the second preset temperature difference, it indicates that the degree to which the water temperature in the upper part of the inner tank 1 exceeds the water temperature in the lower part of the inner tank 1 is relatively large. At this time, by controlling the opening degrees of the first valve 5 and the second valve 6 to respectively adjust the refrigerant flow rates in the first heat exchange channel 204 and the second heat exchange channel 205, the second refrigerant flow rate in the second heat exchange channel 205 is made greater than the first refrigerant flow rate in the first heat exchange channel 204, and the difference between the second refrigerant flow rate and the first refrigerant flow rate is relatively large. The difference between the heating power of the second heat exchange channel 205 for heating the lower part of the inner tank 1 and the heating power of the first heat exchange channel 204 for heating the upper part of the inner tank 1 is relatively large. The water temperatures of the upper part and the lower part of the inner tank 1 can reach the preset temperature in a similar heating time, and at the same time, the energy efficiency can be improved.

[0076] When the difference between the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1 is less than the second preset temperature difference, it indicates that the degree to which the water temperature in the upper part of the inner tank 1 exceeds the water temperature in the lower part of the inner tank 1 is relatively small. At this time, by controlling the opening degrees of the first valve 5 and the second valve 6 to respectively adjust the refrigerant flow rates in the first heat exchange channel 204 and the second heat exchange channel 205, the second refrigerant flow rate in the second heat exchange channel 205 is made greater than the first refrigerant flow rate in the first heat exchange channel 204, and the difference between the second refrigerant flow rate and the first refrigerant flow rate is relatively small. The difference between the heating power of the second heat exchange channel 205 for heating the lower part of the inner tank 1 and the heating power of the first heat exchange channel 204 for heating the upper part of the inner tank 1 is relatively small. The water temperatures of the upper part and the lower part of the inner tank 1 can reach the preset temperature in a similar heating time, and at the same time, the energy efficiency can be improved.

[0077] In a schematic embodiment, the heating method further includes step S6 after step S52 and step S53.

[0078] Step S6: The controller adjusts the refrigerant flow rate of the first heat exchange flow path 204 and the refrigerant flow rate of the second heat exchange flow path 205 in real time based on the difference between the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1. Among them, the refrigerant flow rate of the first heat exchange flow path 204 is positively correlated with the difference, and the refrigerant flow rate of the second heat exchange flow path 205 is negatively correlated with the difference.

[0079] For example, for every one-degree decrease in the difference between the first water temperature in the upper part of the inner tank 1 and the second water temperature in the lower part of the inner tank 1, the opening degree of the first valve 5 is increased by 1%, and the opening degree of the second valve 6 is decreased by 1%.

[0080] In this way, during the heating process, the refrigerant flow rates of the first heat exchange flow path 204 and the second heat exchange flow path 205 become closer as the temperature difference between the water temperature in the upper part of the inner tank 1 and the water temperature in the lower part of the inner tank 1 decreases. As the temperature difference between the water temperature in the upper part of the inner tank 1 and the water temperature in the lower part of the inner tank 1 decreases, the heating power of the first heat exchange flow path 204 for heating the upper part of the inner tank 1 and the heating power of the second heat exchange flow path 205 for heating the lower part of the inner tank 1 also become closer, which is beneficial to improving energy efficiency and making the water temperature in the upper and lower parts of the inner tank 1 uniform.

[0081] In a schematic embodiment, the heating method further includes step S7 and step S8 after step S4 and step S6.

[0082] Step S7: The controller determines whether the stop heating condition is reached. If so, it proceeds to step S8;

[0083] The stop heating condition is that the first water temperature in the upper part of the inner tank 1 is greater than the set temperature, or the second water temperature in the lower part of the inner tank 1 is greater than the set temperature.

[0084] When either the first water temperature in the upper part of the inner tank 1 or the second water temperature in the upper part of the inner tank 1 is greater than the set temperature, it is considered that the stop heating condition has been reached, and the heating of the inner tank 1 can be stopped.

[0085] Step S8: The controller switches the external unit to the standby state, and the external unit stops delivering refrigerant to the first heat exchange flow path 204 and the second heat exchange flow path 205.

[0086] After the stop heating condition is reached, there is no need to continue heating the inner tank 1. The controller controls the external unit to stop delivering refrigerant to the first heat exchange flow path 204 and the second heat exchange flow path 205, saving energy.

[0087] In some embodiments, multiple first temperature sensors 3 are provided. The multiple first temperature sensors 3 are respectively arranged at different positions in the upper part of the inner tank 1. For example, the multiple first temperature sensors 3 are arranged in sequence along the vertical direction in the upper part of the inner tank 1, and the distance between adjacent two first temperature sensors 3 is the same. The first water temperature is the average value of the water temperatures measured by the multiple first temperature sensors 3. Taking the average value of the measurement results of the multiple first temperature sensors 3 as the first water temperature can more accurately reflect the water temperature in the upper part of the inner tank 1.

[0088] In some embodiments, multiple second temperature sensors 4 are provided. The multiple second temperature sensors 4 are respectively arranged at different positions in the lower part of the inner tank 1. For example, the multiple second temperature sensors 4 are arranged in sequence along the vertical direction in the lower part of the inner tank 1, and the distance between adjacent two second temperature sensors 4 is the same. The second water temperature is the average value of the water temperatures measured by the multiple second temperature sensors 4. Taking the average value of the measurement results of the multiple second temperature sensors 4 as the second water temperature can more accurately reflect the water temperature in the lower part of the inner tank 1.

[0089] In a schematic embodiment, a part of the refrigerant flows along the first heat exchange channel 204 from the first end 111 of the cylinder 11 to the middle of the cylinder 11. This part of the refrigerant first heats the water in the first end 111 of the cylinder 11 and then heats the water in the middle of the cylinder 11. Another part of the refrigerant flows along the second heat exchange channel 205 from the second end 112 of the cylinder 11 to the middle of the inner tank 1. This part of the refrigerant first heats the water in the second end 112 of the cylinder 11 and then heats the water in the middle of the cylinder 11. Thus, in the whole heating process, the water in the first end 111 and the second end 112 of the cylinder 11 is preferentially heated, while the temperature of the water in the first end 111 and the second end 112 of the cylinder 11 is increased, and the temperature difference of the water in the first end 111 and the second end 112 of the cylinder 11 is reduced, so that the water temperature distribution in the inner tank 1 is more uniform, improving the user experience.

[0090] In a schematic embodiment, as Figure 1 、 2As shown, the heat exchange assembly 2 includes a first header 21, a second header 22, and a plurality of heat exchange tubes 23. The heat exchange tubes 23, the first header 21, and the second header 22 are all arranged on the outer peripheral wall of the cylinder body 11. The first header 21 and the second header 22 can both be configured as straight tubes. The two ends of the first header 21 respectively extend to the first end 111 and the second end 112 of the cylinder body 11. A plurality of first pipe segments 2111 are arranged in the first header 21, and the plurality of first pipe segments 2111 are arranged in sequence from the first end 111 of the cylinder body 11 to the second end 112 of the cylinder body 11, and two adjacent first pipe segments 2111 are separated from each other. The two ends of the second header 22 respectively extend to the first end 111 and the second end 112 of the cylinder body 11. A plurality of second pipe segments 2211 are arranged in the second header 22, and the plurality of second pipe segments 2211 are arranged in sequence from the first end 111 of the cylinder body 11 to the second end 112 of the cylinder body 11, and two adjacent second pipe segments 2211 are separated from each other. Intervals can be provided between the first pipe segments 2111. The number of the first pipe segments 2111 is one less than the number of the second pipe segments 2211.

[0091] The heat exchange tubes 23 extend along the circumferential direction of the cylinder body 11 closely attached to the outer peripheral wall of the cylinder body 11. One end of the heat exchange tube 23 is connected to the side wall of the first header 21 facing away from the second header 22, and the other end of the heat exchange tube 23 is connected to the side wall of the second header 22. A plurality of heat exchange tubes 23 are provided, and the plurality of heat exchange tubes 23 are arranged side by side in sequence along the axial direction of the cylinder body 11.

[0092] In this embodiment, the first pipe segments 2111 are continuously numbered according to the arrangement order from the first end 111 to the second end 112 of the cylinder 11. For example, if there are n first pipe segments 2111, where n is greater than or equal to 2, the first pipe segment 2111 closest to the first end 111 of the cylinder 11 is the first first pipe segment 2111, and the second pipe segment 2211 closest to the second end 112 of the cylinder 11 is the nth pipe segment. The second pipe segments 2211 are continuously numbered according to the arrangement order from the first end 111 to the second end 112 of the cylinder 11. For example, if there are n + 1 second pipe segments 2211, the second pipe segment 2211 closest to the first end 111 of the cylinder 11 is the first second pipe segment 2211, and the second pipe segment 2211 closest to the second end 112 of the cylinder 11 is the (n + 1)th pipe segment. One end of the ith first pipe segment 2111 is connected to the ith second pipe segment 2211 through the heat exchange tube 23. The other end of the ith first pipe segment 2111 is connected to the (i + 1)th second pipe segment 2211 through the heat exchange tube 23. The heat exchange tube 23 connecting the ith first pipe segment 2111 and the ith second pipe segment 2211 can be one or more. The heat exchange tube 23 connecting the ith first pipe segment 2111 and the (i + 1)th second pipe segment 2211 can be one or more. The first refrigerant inlet 201 is provided on the first second pipe segment 2211, which can be the second pipe segment 2211 at the topmost of the second header 22. The second refrigerant inlet 202 is provided on the last second pipe segment 2211, which can be the second pipe segment 2211 at the bottommost of the second header 22. As Figure 2 shown, when the number of the first pipe segments 2111 is greater than or equal to 3, the refrigerant outlet 203 can be provided on the first pipe segment 2111 in the middle of the first header 21; as Figure 3 shown, when the number of the second pipe segments 2211 is greater than or equal to 3, the refrigerant outlet 203 can also be provided on the second pipe segment 2211 in the middle of the second header 22.

[0093] In this way, a part of the first pipe segments 2111, the heat exchange tubes 23 and the second pipe segments 2211 can connect the first refrigerant inlet 201 and the refrigerant outlet 203. The first pipe segments 2111, the heat exchange tubes 23 and the second pipe segments 2211 connecting the first refrigerant inlet 201 and the refrigerant outlet 203 form the first heat exchange flow path 204. A part of the first pipe segments 2111, the heat exchange tubes 23 and the second pipe segments 2211 can connect the second refrigerant inlet 202 and the refrigerant outlet 203. The first pipe segments 2111, the heat exchange tubes 23 and the second pipe segments 2211 connecting the second refrigerant inlet 202 and the refrigerant outlet 203 form the second heat exchange flow path 205. The heat exchange component 2 with this structure is simple in structure and low in manufacturing cost.

[0094] In a schematic embodiment, the first header 21 includes a first pipe body 211 and a first partition 212. The extending direction of the first pipe body 211 is parallel to the axial direction of the cylinder body 11. Both ends of the first pipe body 211 are closed. One or more first partitions 212 may be provided. The first partition 212 is disposed within the first pipe body 211. The first partitions 212 are arranged in sequence along the axial direction of the first pipe body 211. The first partitions 212 are separated from each other within the first pipe body 211. One or more first partitions 212 divide the first pipe body 211 into a plurality of first pipe segments 2111. The number of the first pipe segments 2111 is one more than the number of the first partitions 212. The first partition 212 may be configured as a flat plate.

[0095] The second header 22 includes a second pipe body 221 and a second partition 222. The extending direction of the second pipe body 221 is parallel to the axial direction of the cylinder body 11. The length of the second pipe body 221 may be the same as the length of the first pipe body 211. Both ends of the second pipe body 221 are closed.

[0096] A plurality of second partitions 222 are provided, and the number of the second partitions 222 may be one more than the number of the first partitions 212.

[0097] All the second partitions 222 are disposed within the second pipe body 221. The second partitions 222 are arranged in sequence along the axial direction of the second pipe body 221. The second partitions 222 are separated from each other within the second pipe body 221. The plurality of second partitions 222 divide the second pipe body 221 into a plurality of second pipe segments 2211. The number of the second pipe segments 2211 is one more than the number of the second partitions 222. The second partition 222 may be configured as a flat plate, and the second partition 222 is perpendicular to the extending direction of the second header 22. The flow-through areas of the first pipe body 211 and the second pipe body 221 may be larger than the flow-through area of the heat exchange pipe 23.

[0098] The structures of the first header 21 and the second header 22 are simple and easy to manufacture.

[0099] In a schematic embodiment, as Figure 2 shown, two first partitions 212 are disposed within the first pipe body 211, and the two first partitions 212 divide the first pipe body 211 into three first pipe segments 2111. Three second partitions 222 are disposed within the second pipe body 221, and the three second partitions 222 divide the second pipe body 221 into four second pipe segments 2211.

[0100] The upward end of the first first pipe segment 2111a is connected to the first second pipe segment 2211a through the heat exchange pipe 23. The downward end of the first first pipe segment 2111a is connected to the upward end of the second second pipe segment 2211b through the heat exchange pipe 23. The upward end of the second first pipe segment 2111b is connected to the downward end of the second second pipe segment 2211b through the heat exchange pipe 23. The downward end of the second first pipe segment 2111b is connected to the upward end of the third second pipe segment 2211c through the heat exchange pipe 23. The upward end of the third first pipe segment 2111c is connected to the downward end of the third second pipe segment 2211c through the heat exchange pipe 23. The downward end of the third first pipe segment 2111c is connected to the fourth second pipe segment 2211d through the heat exchange pipe 23.

[0101] The refrigerant outlet 203 is provided on the middle first pipe segment 2111, that is, the second first pipe segment 2111b. The refrigerant outlet 203 can be provided in the middle of the second first pipe segment 2111b. The first refrigerant inlet 201 is provided on the first second pipe segment 2211a, and the second refrigerant inlet 202 is provided on the fourth second pipe segment 2211d.

[0102] Thus, a part of the refrigerant can be injected from the first refrigerant inlet 201 into the first second pipe segment 2211a, and successively flow through the heat exchange pipe 23 between the first first pipe segment 2111a and the first second pipe segment 2211a, the first first pipe segment 2111a, the heat exchange pipe 23 between the first first pipe segment 2111a and the second second pipe segment 2211b, the second second pipe segment 2211b, the heat exchange pipe 23 between the second second pipe segment 2211b and the second first pipe segment 2111b and reach the second first pipe segment 2111b, and finally flow out from the refrigerant outlet 203 on the second first pipe segment 2111b. Another part of the refrigerant can be injected from the second refrigerant inlet 202 into the fourth second pipe segment 2211d, and successively flow through the heat exchange pipe 23 between the fourth second pipe segment 2211d and the third first pipe segment 2111c, the third first pipe segment 2111c, the heat exchange pipe 23 between the third first pipe segment 2111c and the third second pipe segment 2211c, the third second pipe segment 2211c, the heat exchange pipe 23 between the third second pipe segment 2211c and the second first pipe segment 2111b and reach the second first pipe segment 2111b, and finally flow out from the refrigerant outlet 203 on the second first pipe segment 2111b.

[0103] In another exemplary embodiment, as Figure 3As shown, a first partition member 212 is provided inside the first pipe body 211, and the first partition member 212 divides the first pipe body 211 into two first pipe segments 2111. Two second partition members 222 are provided inside the second pipe body 221, and the two second partition members 222 divide the second pipe body 221 into three second pipe segments 2211.

[0104] The upward end of the first first pipe segment 2111a is connected to the first second pipe segment 2211a through the heat exchange pipe 23. The downward end of the first first pipe segment 2111a is connected to the upward end of the second second pipe segment 2211b through the heat exchange pipe 23. The upward end of the second first pipe segment 2111b is connected to the downward end of the second second pipe segment 2211b through the heat exchange pipe 23. The downward end of the second first pipe segment 2111b is connected to the third second pipe segment 2211c through the heat exchange pipe 23.

[0105] The refrigerant outlet 203 is provided on the second pipe segment 2211 in the middle, that is, the second second pipe segment 2211b. The refrigerant outlet 203 may be provided in the middle of the second first pipe segment 2111b. The first refrigerant inlet 201 is provided on the first second pipe segment 2211a, and the second refrigerant inlet 202 is provided on the third second pipe segment 2211c.

[0106] Thus, a part of the refrigerant can be injected from the first refrigerant inlet 201 into the first second pipe segment 2211a, and successively flow through the heat exchange pipe 23 between the first first pipe segment 2111a and the first second pipe segment 2211a, the first first pipe segment 2111a, and the heat exchange pipe 23 between the first first pipe segment 2111a and the second second pipe segment 2211b to reach the second second pipe segment 2211b, and finally flow out from the refrigerant outlet 203 on the second second pipe segment 2211b. Another part of the refrigerant can be injected from the second refrigerant inlet 202 into the third second pipe segment 2211c, and successively flow through the heat exchange pipe 23 between the third second pipe segment 2211c and the second first pipe segment 2111b, the second first pipe segment 2111b, and the heat exchange pipe 23 between the second first pipe segment 2111b and the second second pipe segment 2211b to reach the second second pipe segment 2211b, and finally flow out from the refrigerant outlet 203 on the second second pipe segment 2211b.

[0107] In a schematic embodiment, the extending direction of the heat exchange tube 23 is the circumferential direction of the cylindrical body 11. The heat exchange tube 23 is hoop-shaped on the outer peripheral wall of the cylindrical body 11. The heat exchange tube 23 is configured as an arc-shaped tube. The radian of the heat exchange tube 23 is greater than π. The radian of the heat exchange tube 23 is greater than or equal to 300π / 180. All the heat exchange tubes 23 extend from the side wall of the first header 21 on the side facing away from the second header 22 to the side wall of the second header 22 on the side facing away from the first header 21. The heat exchange tube 23 can be made of a metal tube. The metal tube has elasticity and can be hoop-shaped on the outer peripheral wall of the cylindrical body 11 through elastic deformation by bending, so that the heat exchange tube 23 is closely attached to the outer peripheral wall of the cylindrical body 11. There is no need to fix the heat exchange tube 23 on the cylindrical body 11 through a connecting piece, and the installation of the heat exchange tube 23 is more convenient.

[0108] In a schematic embodiment, the heat exchange tube 23 is configured as a microchannel flat tube. The cross-section of the microchannel flat tube is flat. The flat tube is beneficial to fitting the outer peripheral wall of the inner tank 1. Compared with a circular tube, under the same heat exchange capacity, it is lighter in weight, the effective heat exchange area is increased, and the refrigerant charge can also be effectively reduced. Each microchannel flat tube is provided with a plurality of refrigerant flow channels, and each refrigerant flow channel extends from one end of the microchannel flat tube to the other end of the microchannel flat tube, so as to further increase the contact area between the refrigerant flowing through the microchannel flat tube and the microchannel flat tube, and further improve the heat exchange efficiency.

[0109] In a schematic embodiment, as Figure 1 shown, the heat exchange assembly 2 further includes an input pipe assembly 26, an output pipe 27, and a refrigerant interface assembly 25.

[0110] The refrigerant interface assembly 25 includes a base 251, an input joint 252, and an output joint 253. The base 251 is configured as a support structure. The base 251 can be welded to the outer peripheral wall of the cylindrical body 11, on the side of the first header 21 facing away from the heat exchange tube 23 and on the side of the second header 22 facing away from the heat exchange tube 23. The input joint 252 and the output joint 253 are both arranged on the base 251. One end of the input joint 252 faces the cylindrical body 11, and the other end faces away from the cylindrical body 11. One end of the output joint 253 faces the cylindrical body 11, and the other end faces away from the cylindrical body 11. The input joint 252 can be a high-pressure pipe joint. The output joint 253 can be a low-pressure pipe joint.

[0111] The input pipe assembly 26 includes a three-way pipe fitting 262, a main pipe 261, a first branch pipe 263, and a second branch pipe 264. The three-way pipe fitting 262 is provided with three interfaces that communicate with each other. One end of the main pipe 261 is connected to one end of the input joint 252 facing the cylinder body 11, and the other end of the main pipe 261 is connected to the first interface of the three-way pipe fitting 262. The second interface of the three-way pipe fitting 262 is connected to one end of the first branch pipe 263, and the other end of the first branch pipe 263 is connected to the first refrigerant inlet 201 of the heat exchange assembly 2. The third interface of the three-way pipe fitting 262 is connected to one end of the second branch pipe 264, and the other end of the second branch pipe 264 is connected to the second refrigerant inlet 202 of the heat exchange assembly 2. The first valve 5 is arranged on the first branch pipe 263. The second valve 6 is arranged on the second branch pipe 264.

[0112] One end of the output pipe 27 is connected to one end of the output joint 253 facing the cylinder body 11, and the other end of the output pipe 27 is connected to the output joint 253 of the heat exchange assembly 2.

[0113] The input joint 252 and the output joint 253 can be externally connected to a refrigerant pipeline for connecting to an external unit. The input joint 252 is used to receive refrigerant, and the output joint 253 is used to output refrigerant. The external unit injects refrigerant into the input joint 252, and the refrigerant is injected into the first refrigerant inlet 201 and the second refrigerant inlet 202 of the heat exchange assembly 2 through the input pipe assembly 26. Specifically, the refrigerant enters the main pipe 261 from the input joint 252, and then is split by the three-way pipe fitting 262 into the first branch pipe 263 and the second branch pipe 264. A part of the refrigerant flows through the first branch pipe 263 and is injected into the first refrigerant inlet 201, and another part of the refrigerant flows through the second branch pipe 264 and is injected into the second refrigerant inlet 202. The refrigerant in the heat exchange assembly 2 is output from the heat exchange assembly 2 through the refrigerant outlet 203, the output pipe 27, and the output joint 253 and returns to the external unit.

[0114] In a schematic embodiment, the heat exchange assembly 2 further includes a plurality of connecting members 24. The plurality of connecting members 24 are respectively arranged on the first header 21 and the second header 22. A plurality of connecting members 24 can be arranged on the pipe walls of the first header 21 and the second header 22. The connecting members 24 on the first header 21 connect the first header 21 to the cylinder body 11 of the inner tank 1. The connecting members 24 on the second header 22 connect the second header 22 to the cylinder body 11 of the inner tank 1.

[0115] In a schematic embodiment, the water heater further includes a housing 8 and a heat insulation layer 7. The housing 8 is configured as a hollow structure with a cylindrical outer contour. The inner tank 1 and the heat exchange assembly 2 are both arranged in the housing 8. The heat insulation layer 7 is filled in the gaps between the inner tank 1 and the housing 8 and between the heat exchange assembly 2 and the housing 8. The heat insulation layer 7 can be made of a foaming material, and the heat conduction performance of the heat insulation layer 7 is poor, which can insulate the inner tank 1 and the heat exchange assembly 2.

[0116] In a schematic embodiment, the heat exchange assembly 2 includes two heat exchangers. One heat exchanger is disposed at the first end 111 of the cylinder 11, and the other heat exchanger is disposed at the second end 112 of the cylinder 11. The first heat exchange flow channel 204 is disposed in the heat exchanger located at the first end 111 of the cylinder 11, and the second heat exchange flow channel 205 is disposed in the heat exchanger located at the second end 112 of the cylinder 11.

[0117] In a schematic embodiment, the heat exchange assembly 2 includes one heat exchanger, and both the first heat exchange flow channel 204 and the second heat exchange flow channel 205 are disposed in this heat exchanger.

[0118] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "one side", "the other side", "one end", "the other end", "side", "opposite", "four corners", "periphery", "the structure of the character 'kou'", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the structure referred to has a specific orientation, is constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention.

[0119] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "connection", "direct connection", "indirect connection", "fixed connection", "installation", "assembly" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; the terms "installation", "connection", "fixed connection" may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0120] Although the disclosed embodiments of the present invention are as above, the content described is only the embodiments adopted for the convenience of understanding the present invention and is not used to limit the present invention. Any person skilled in the art within the scope of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be defined by the appended claims.

Claims

1. A heating method for a water heater, characterized in that, The water heater includes an inner tank with upper water outlet and lower water inlet, and a heat exchange component. The heat exchange component includes a first heat exchange flow channel disposed at the upper part of the inner tank and a second heat exchange flow channel disposed at the lower part of the inner tank; The heating method includes: Based on reaching the heating condition and the difference between the set temperature and the first water temperature in the upper part of the inner tank being less than the first preset temperature difference, only deliver refrigerant to the second heat exchange flow channel to heat the lower part of the inner tank.

2. The heating method according to claim 1, wherein: Based on reaching the heating condition and the difference between the set temperature and the first water temperature in the upper part of the inner tank being greater than or equal to the first preset temperature difference, deliver refrigerant to the first heat exchange flow channel and the second heat exchange flow channel simultaneously to heat the upper and lower parts of the inner tank simultaneously.

3. The heating method according to claim 2, characterized in that When delivering refrigerant to the first heat exchange flow channel and the second heat exchange flow channel to heat the upper and lower parts of the inner tank simultaneously, the refrigerant flow rate in the second heat exchange flow channel is greater than the refrigerant flow rate in the first heat exchange flow channel.

4. The heating method according to claim 2, wherein The delivering refrigerant to the first heat exchange flow channel and the second heat exchange flow channel to heat the upper and lower parts of the inner tank simultaneously includes: Based on the difference between the first water temperature and the second water temperature in the lower part of the inner tank being greater than or equal to the second preset temperature difference, deliver refrigerant to the first heat exchange flow channel at a first refrigerant flow rate and deliver refrigerant to the second heat exchange flow channel at a second refrigerant flow rate; Based on the difference between the first water temperature and the second water temperature being less than the second preset temperature difference, deliver refrigerant to the first heat exchange flow channel at a third refrigerant flow rate and deliver refrigerant to the second heat exchange flow channel at a fourth refrigerant flow rate; Wherein, the second refrigerant flow rate is greater than the fourth refrigerant flow rate, and the third refrigerant flow rate is greater than the first refrigerant flow rate.

5. The heating method according to claim 2, characterized in that, After delivering refrigerant to the first heat exchange flow channel and the second heat exchange flow channel, the heating method further includes: Adjusting the refrigerant flow rate of the first heat exchange flow channel based on the difference between the first water temperature and the second water temperature in the lower part of the inner tank, and the refrigerant flow rate of the first heat exchange flow channel is positively correlated with the difference; and / or, Adjusting the refrigerant flow rate of the second heat exchange flow channel based on the difference between the first water temperature and the second water temperature in the lower part of the inner tank, and the refrigerant flow rate of the second heat exchange flow channel is negatively correlated with the difference.

6. The heating method according to claim 5, wherein The water heater further includes an external unit for delivering refrigerant to the first heat exchange flow channel and the second heat exchange flow channel, a first valve disposed on the pipeline between the external unit and the first heat exchange flow channel, and a second valve disposed on the pipeline between the external unit and the second heat exchange flow channel; Control the refrigerant flow rate of the first heat exchange flow channel by controlling the opening degree of the first valve, and control the refrigerant flow rate of the second heat exchange flow channel by controlling the opening degree of the second valve.

7. The heating method according to any one of claims 1 to 4, characterized in that The heating condition is: the first water temperature in the upper part of the inner tank is less than the set temperature, or the second water temperature in the lower part of the inner tank is less than the sum of the set temperature and the preset temperature.

8. The heating method according to any one of claims 1 to 4, characterized in that, The heating method further includes: Based on reaching the stop heating condition, stop delivering refrigerant to the first heat exchange flow channel and the second heat exchange flow channel.

9. The heating method according to claim 8, wherein The stop heating condition is: the first water temperature is greater than the set temperature, or the second water temperature in the lower part of the inner tank is greater than the set temperature.

10. A water heater, characterized in that, Includes: Inner tank; The heat exchange assembly includes a first heat exchange flow channel arranged at the upper part of the inner tank and a second heat exchange flow channel arranged at the lower part of the inner tank; The outdoor unit is connected to the first heat exchange flow channel and the second heat exchange flow channel through pipelines; The first valve is arranged on the pipeline connecting the outdoor unit and the first heat exchange flow channel; The second valve is arranged on the pipeline connecting the outdoor unit and the second heat exchange flow channel; The first temperature sensor is used to detect the first water temperature in the upper part of the inner tank; The second temperature sensor is used to detect the second water temperature in the lower part of the inner tank; The controller is electrically connected to the first valve, the second valve, the outdoor unit, the first temperature sensor and the second temperature sensor, and is configured to: Based on reaching the heating condition and the difference between the set temperature and the first water temperature being less than the first preset temperature difference, close the first valve and open the second valve, and drive the outdoor unit to only deliver refrigerant to the second heat exchange flow channel to heat the lower part of the inner tank.

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