CN112283933B - Control method of electric water heater with double inner containers for parallel heating and serial heat exchange - Google Patents

Abstract

An electric water heater with double inner tanks for parallel heating and series heat exchange and a control method thereof, the electric water heater with double inner tanks for parallel heating and series heat exchange comprises a second inner tank and a first inner tank, a second spirally wound tube heat exchanger is arranged in the second inner tank, one end of a second pure water inlet pipe is inserted into the second inner tank and opens at the bottom of the second inner tank, one end of a second pure water overflow pipe is inserted into the second inner tank and opens at the upper part of the second inner tank, one end of a second water inlet pipe is inserted into the second inner tank and connected to the lowest part of the second spirally wound tube heat exchanger, one end of a second water outlet pipe is inserted into the second inner tank and connected to the highest part of the second spirally wound tube heat exchanger; the inner wall of the second inner tank and the outer wall of the second spirally wound tube heat exchanger together form a second volume for storing pure water; the first inner tank is provided with a first spirally wound tube heat exchanger. The present invention has the characteristics of high heat exchange efficiency and maximum hot water energy conversion output rate.

Description

A control method for an electric water heater with double inner tanks for parallel heating and series heat exchange

Technical Field

The invention relates to a control method for an electric water heater with double inner tanks for parallel heating and series heat exchange.

Background technique

Chinese patent document number CN1264021A disclosed a double-tank electric water heater on August 23, 2000, in particular, an electric water heater using two series-connected tanks as a water storage tank, which is composed of a control box with an indicator light, a conversion switch, a knob, a thermostat, and a temperature limiter connected to a shell with an insulation layer and a water storage tank, and the water storage tank is composed of two or more tanks with water inlet pipes or water outlet pipes connected as a whole through a connecting pipe. The working efficiency of this double-tank electric water heater is not high enough, and there are safety hazards, which need to be improved.

Summary of the invention

The purpose of the present invention is to provide a control method for an electric water heater with double inner tanks for parallel heating and series heat exchange with high heat exchange efficiency, so as to overcome the shortcomings of the prior art.

A control method for a double-tank parallel heating and series heat exchange electric water heater designed for this purpose comprises a second tank and a first tank, and its structural feature is that

A second spirally wound tube heat exchanger is arranged in the second inner tank, one end of a second pure water inlet pipe is inserted into the second inner tank and opens at the bottom of the second inner tank, one end of a second pure water overflow pipe is inserted into the second inner tank and opens at the upper part of the second inner tank, one end of a second water inlet pipe is inserted into the second inner tank and communicates with the lowest part of the second spirally wound tube heat exchanger, one end of a second water outlet pipe is inserted into the second inner tank and communicates with the highest part of the second spirally wound tube heat exchanger; the second inner tank contains pure water as second preheated water, and the second spirally wound tube heat exchanger is immersed in the second preheated water;

A first spirally wound tube heat exchanger is arranged in the first inner tank, one end of a first pure water inlet pipe is inserted into the first inner tank and opens at the bottom of the first inner tank, one end of a first pure water overflow pipe is inserted into the first inner tank and opens at the upper part of the first inner tank, one end of a first water inlet pipe is inserted into the first inner tank and communicates with the lowest part of the first spirally wound tube heat exchanger, one end of a first water outlet pipe is inserted into the first inner tank and communicates with the highest part of the first spirally wound tube heat exchanger; the first inner tank contains pure water as first preheated water, and the first spirally wound tube heat exchanger is immersed in the first preheated water;

The other end of the second water inlet pipe is connected to the other end of the first water outlet pipe;

A second cavity is provided between one end of the second pure water overflow pipe and the top inner wall of the second inner container, and a first cavity is provided between one end of the first pure water overflow pipe and the top inner wall of the first inner container.

Furthermore, the second inner tank is provided with a second electric heater and a second liquid level sensor electrically connected to the electric control board of the electric water heater, and the first inner tank is provided with a first electric heater and a first liquid level sensor electrically connected to the electric control board.

Furthermore, the second electric heater is arranged in parallel with the first electric heater.

Furthermore, a second electronic thermometer electrically connected to the electronic control board is provided in the second inner pot, and a temperature sensing end of the second electronic thermometer is inserted into the middle part of the second inner pot; a first electronic thermometer electrically connected to the electronic control board is provided in the first inner pot, and a temperature sensing end of the second electronic thermometer is inserted into the middle part of the first inner pot; wherein, the preset temperature of the second electronic thermometer is T2, the preset temperature of the first electronic thermometer is T1, and T2 is greater than or equal to T1.

Furthermore, it also includes an instant electromagnetic water heater or an instant electric water heater electrically connected to the electrical control board, the tap water inlet pipe is connected to the water inlet of the instant electromagnetic water heater or the instant electric water heater, and the water outlet of the instant electromagnetic water heater or the instant electric water heater is connected to the other end of the first water inlet pipe; a Hall water flow sensor electrically connected to the electrical control board is provided on the water inlet of the instant electromagnetic water heater or the instant electric water heater.

Furthermore, it also includes a mechanical water mixing thermostatic valve, the tap water inlet pipe is connected to the cold water inlet of the mechanical water mixing thermostatic valve, and the other end of the second water outlet pipe is connected to the hot water inlet of the mechanical water mixing thermostatic valve.

Furthermore, it also includes a water inlet tee, the tap water inlet pipe is connected to the water inlet of the water inlet tee, the first water outlet of the water inlet tee is connected to the water inlet of the instant electromagnetic water heater or the instant electric water heater, and the second water outlet of the water inlet tee is connected to the cold water inlet of the mechanical water mixing thermostatic valve.

Furthermore, the second spirally wound tube heat exchanger and/or the first spirally wound tube heat exchanger is a uniformly spaced uniformly distributed spirally wound tube heat exchanger or a segmented spirally wound tube heat exchanger.

A control method for an electric water heater with two inner tanks connected in parallel for heating and in series for heat exchange, characterized in that it comprises the following steps:

Step 1, preparation;

Pure water enters the first inner tank through one end of the first pure water inlet pipe. When the pure water level in the first inner tank reaches one end of the first pure water overflow pipe, the pure water level in the first inner tank reaches equilibrium, and the second cavity is located above the pure water level in the first inner tank. At this time, the pure water in the first inner tank becomes the first preheated water.

Pure water enters the second inner tank through one end of the second pure water inlet pipe. When the pure water level in the second inner tank reaches one end of the second pure water overflow pipe, the pure water level in the second inner tank reaches equilibrium, and the first cavity is located above the pure water level in the second inner tank. At this time, the pure water in the second inner tank becomes the second preheated water.

Step 2: preheating;

The maximum temperature of the first electronic thermometer used to control whether the first electric heater works is set to T1, and the maximum temperature of the second electronic thermometer used to control whether the second electric heater works is set to T2, and T2 is greater than or equal to T1;

respectively start the second electric heater and the first electric heater through the electric control panel;

When the temperature of the first preheated water sampled in time by the first electronic thermometer reaches T1, the electric control board electrically connected to the first electronic thermometer cuts off the working power of the first electric heater by bipolar. When the temperature of the first preheated water sampled in time by the first electronic thermometer is lower than T1, the electric control board electrically connected to the first electronic thermometer turns on the working power of the first electric heater, and the first electric heater starts working again.

When the temperature of the second preheated water timely sampled by the second electronic thermometer reaches T2, the electric control board electrically connected to the second electronic thermometer bipolarly cuts off the working power of the second electric heater; when the temperature of the second preheated water timely sampled by the second electronic thermometer is lower than T2, the electric control board electrically connected to the second electronic thermometer turns on the working power of the second electric heater, and the second electric heater resumes operation;

Step 3, heat exchange;

When the Hall water flow sensor electrically connected to the electric control board and arranged on the water inlet of the instant electromagnetic water heater or the instant electric water heater detects a water flow signal, the electric control board cuts off the working power of the second electric heater and the first electric heater in a bipolar manner, and the electric control board starts the working power of the instant electromagnetic water heater or the instant electric water heater;

The tap water enters the instant electromagnetic water heater or instant electric water heater through the tap water inlet pipe, is heated and sterilized for the first time, and then becomes the first heated water.

The first heating water flows from the water outlet of the instant electromagnetic water heater or the instant electric water heater to the other end of the first water inlet pipe, then enters the lowest point of the first spirally wound tube heat exchanger from one end of the first water inlet pipe, then reaches the highest point of the first spirally wound tube heat exchanger, and finally flows out from the other end of the first water outlet pipe connected to the highest point of the first spirally wound tube heat exchanger; the first heating water is heated for the second time by the first preheated water when flowing through the first spirally wound tube heat exchanger to become the second heating water with a temperature of T3;

The second heating water enters the lowest point of the second spirally wound tube heat exchanger through the other end of the first water outlet pipe, then reaches the highest point of the second spirally wound tube heat exchanger, and finally flows out from the other end of the second water outlet pipe connected to the highest point of the second spirally wound tube heat exchanger; the second heating water is heated for the third time by the second preheated water when flowing through the second spirally wound tube heat exchanger to become the third heating water with a temperature of T4;

The third heated water flows to the hot water inlet of the mechanical water mixing thermostatic valve through the other end of the second water outlet pipe, and the tap water flows to the cold water inlet of the mechanical water mixing thermostatic valve through the tap water inlet pipe. The user can obtain hot water with suitable temperature by manually adjusting the opening of the mechanical water mixing thermostatic valve.

Further, the method further comprises the following steps:

Step 4. After the product is started, when the sampling temperature of the first preheated water remains at T1 without changing within 5 to 30 seconds, the electric control board bipolarly cuts off the working power of the first electric heater; when the sampling temperature of the first preheated water remains at T2 without changing within 5 to 30 seconds, the electric control board bipolarly cuts off the working power of the second electric heater.

The second inner tank in the present invention is provided with a second spirally wound tube heat exchanger, and the inner wall of the second inner tank and the outer wall of the second spirally wound tube heat exchanger together form a second volume for storing pure water, and the pure water is the second heating water; the first inner tank is provided with a first spirally wound tube heat exchanger, and the inner wall of the first inner tank and the outer wall of the first spirally wound tube heat exchanger together form a first volume for storing pure water, and the pure water is the first heating water; by arranging two parallel electric heaters: the first electric heater and the second electric heater, respectively, in two parallel inner tanks: that is, the first inner tank and the second inner tank in parallel; the first spirally wound tube heat exchanger and the first inner tank are connected in parallel. The two spirally wound tube heat exchangers are arranged in series; the water entering the first spirally wound tube heat exchanger and the second spirally wound tube heat exchanger is heated respectively by preheating the first preheated water and the second preheated water in advance, thereby improving the heating efficiency of tap water, that is, maximizing the hot water energy exchange output rate, and improving the endurance of the product; by arranging the first cavity and the second cavity and the first pure water overflow pipe and the second pure water overflow pipe, the first preheated water and the second preheated water in the second inner tank and the first inner tank can be prevented from being overfilled, and the second inner tank and the first inner tank can be prevented from becoming pressure vessels due to heat, thereby improving the safety performance of the product.

The first preheated water and the second preheated water in the present invention are heated in advance before the tap water used by the user for bathing enters the first spirally wound tube heat exchanger; when the Hall water flow sensor electrically connected to the electric control board and arranged on the water inlet of the instant electromagnetic water heater or the instant electric water heater detects a water flow signal, that is, when it detects that the user is ready to use hot water, the electric control board cuts off the working power of the second electric heater and the first electric heater in bipolar manner, and at this time, regardless of whether the first preheated water and/or the second preheated water are heated to the predetermined temperature of the first electronic thermometer and/or the second electronic thermometer, they must be cut off in bipolar manner, that is, the neutral line and the live line are disconnected, so as to stop heating the first preheated water and the second preheated water, that is, completely realize water-electricity separation and ensure user safety. Only when the Hall water flow sensor does not detect a water flow signal can the first preheated water and the second preheated water be heated again.

The present invention also includes an instant electromagnetic water heater or an instant electric water heater electrically connected to the electric control board, the tap water inlet pipe is connected to the water inlet of the instant electromagnetic water heater or the instant electric water heater, and the water outlet of the instant electromagnetic water heater or the instant electric water heater is connected to the other end of the first water inlet pipe; a Hall water flow sensor electrically connected to the electric control board is arranged on the water inlet of the instant electromagnetic water heater or the instant electric water heater; by heating the instant electromagnetic water heater or the instant electric water heater and the first inner tank and the second inner tank, scale can be effectively prevented from accumulating in the instant electromagnetic water heater or the instant electric water heater, or in the first spirally wound tube heat exchanger and the second spirally wound tube heat exchanger, because the first spirally wound tube heat exchanger is immersed in the first preheated water. In the process, the first preheated water is pure water, and during the heating of the pure water, basically no scale is generated on the surfaces of the first spirally wound tubular heat exchanger and the second spirally wound tubular heat exchanger. Similarly, the second spirally wound tubular heat exchanger is immersed in the second preheated water, and scale will not accumulate on the outer wall and the inner wall of the second spirally wound tubular heat exchanger. The tap water in the instant electromagnetic water heater or the instant electric water heater, the first spirally wound tubular heat exchanger and the second spirally wound tubular heat exchanger is under the pressure of the tap water in the pipe network during the heating process. Even if scale is generated, it will be quickly taken away and will not accumulate on the inner walls of the instant electromagnetic water heater or the instant electric water heater, the first spirally wound tubular heat exchanger and the second spirally wound tubular heat exchanger, respectively, thereby improving the heat transfer efficiency and reducing safety hazards.

The first inner tank and the second inner tank in the present invention are preheated and stored in parallel, and the first inner tank and the second inner tank are connected in series with the instant electromagnetic water heater or the instant electric water heater for heat exchange, so that the product can achieve the characteristics of high hot water heat exchange efficiency and maximized hot water energy exchange output rate.

The tap water inlet pipe in the present invention is connected to the cold water inlet of the mechanical water mixing thermostatic valve, and the other end of the second water outlet pipe is connected to the hot water inlet of the mechanical water mixing thermostatic valve; through the pressure balance of the tap water in the pipeline network, the tap water can flow into the instant electromagnetic water heater and the mechanical water mixing thermostatic valve respectively, thereby simplifying the control components and reducing the production cost.

The second spirally wound tube heat exchanger and/or the first spirally wound tube heat exchanger in the present invention is a uniformly spaced uniform spirally wound tube heat exchanger or a segmented spirally wound tube heat exchanger; when the second spirally wound tube heat exchanger and/or the first spirally wound tube heat exchanger is a segmented spirally wound tube heat exchanger, the efficiency of heat exchange can be further improved.

In summary, the present invention has the characteristics of high heat exchange efficiency and maximized hot water energy conversion output rate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of an embodiment of the present invention.

FIG. 2 is an application example of the present invention.

FIG3 is a control block diagram of the present invention.

In the figure: 1 is the second electronic thermometer, 2 is the second pure water overflow pipe, 3 is the second water outlet pipe, 4 is the second spirally wound tube heat exchanger, 5 is the second electric heater, 6 is the first electronic thermometer, 7 is the first pure water overflow pipe, 8 is the first water outlet pipe, 9 is the first spirally wound tube heat exchanger, 10 is the first electric heater, 11 is the second water inlet pipe, 12 is the second pure water inlet pipe, 13 is the first water inlet pipe, 14 is the first pure water inlet pipe, 17 is the second liquid level sensor, 18 is the first liquid level sensor, 19 is the Hall water flow sensor, 20 is the second inner tank, 30 is the first inner tank, 40 is the instant electromagnetic water heater, 50 is the mechanical water mixing thermostatic valve, and 60 is the water inlet tee.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Referring to Fig. 1 to Fig. 3, the electric water heater with double inner tanks for parallel heating and series heat exchange comprises a second inner tank 20 and a first inner tank 30, wherein a second spirally wound tubular heat exchanger 4 is arranged in the second inner tank 20, one end of a second pure water inlet pipe 12 is inserted into the second inner tank 20 and opens at the bottom of the second inner tank 20, one end of a second pure water overflow pipe 2 is inserted into the second inner tank 20 and opens at the upper part of the second inner tank 20, one end of a second water inlet pipe 11 is inserted into the second inner tank 20 and communicates with the lowest part of the second spirally wound tubular heat exchanger 4, one end of a second water outlet pipe 3 is inserted into the second inner tank 20 and communicates with the highest part of the second spirally wound tubular heat exchanger 4; the inner wall of the second inner tank 20 and the outer wall of the second spirally wound tubular heat exchanger 4 together form a second volume for storing pure water; the second inner tank 20 is filled with pure water as second preheated water, and the second spirally wound tubular heat exchanger 4 is immersed in the second preheated water;

The first inner liner 30 is provided with a first spirally wound tube heat exchanger 9, one end of the first pure water inlet pipe 14 is inserted into the first inner liner 30 and opens at the bottom of the first inner liner 30, one end of the first pure water overflow pipe 7 is inserted into the first inner liner 30 and opens at the upper part of the first inner liner 30, one end of the first water inlet pipe 13 is inserted into the first inner liner 30 and communicates with the lowest part of the first spirally wound tube heat exchanger 9, and one end of the first water outlet pipe 8 is inserted into the first inner liner 30 and communicates with the highest part of the first spirally wound tube heat exchanger 9; the inner wall of the first inner liner 30 and the outer wall of the first spirally wound tube heat exchanger 9 together form a first volume for storing pure water; the first inner liner 30 is filled with pure water as the first preheated water, and the first spirally wound tube heat exchanger 9 is immersed in the first preheated water;

The other end of the second water inlet pipe 11 is connected to the other end of the first water outlet pipe 8; a second cavity is provided between one end of the second pure water overflow pipe 2 and the top inner wall of the second inner tank 20, and a first cavity is provided between one end of the first pure water overflow pipe 7 and the top inner wall of the first inner tank 30.

In this embodiment, a second heat-insulating layer can be provided on the outer wall of the second inner liner 20 and a first heat-insulating layer can be provided on the outer wall of the first inner liner 30 as required.

During long-term use of this product, pure water may be partially lost due to evaporation or other reasons, which may cause the liquid level to drop. By setting a liquid level sensor, it can automatically alarm and prompt to add pure water, thereby maintaining the normal operation of this product.

In this embodiment, the second inner tank 20 is provided with a second electric heater 5 and a second liquid level sensor 17 which are electrically connected to the electric control board of the electric water heater respectively, and the first inner tank 30 is provided with a first electric heater 10 and a first liquid level sensor 18 which are electrically connected to the electric control board respectively.

The second electric heater 5 is arranged in parallel with the first electric heater 10. The heating power of the second electric heater 5 may be equal to or different from the heating power of the first electric heater 10, because the volumes of the second inner liner 20 and the first inner liner 30 may be different or the same.

The second inner pot 20 is provided with a second electronic thermometer 1 electrically connected to the electric control board, and the temperature sensing end of the second electronic thermometer 1 is inserted into the middle of the second inner pot 20; the first inner pot 30 is provided with a first electronic thermometer 6 electrically connected to the electric control board, and the temperature sensing end of the second electronic thermometer 6 is inserted into the middle of the first inner pot 30. The preset temperature of the second electronic thermometer 1 is T2, and the preset temperature of the first electronic thermometer 6 is T1, and T2 is greater than or equal to T1.

In this embodiment, it also includes an instant electromagnetic water heater 40 or an instant electric water heater electrically connected to the electrical control board, the tap water inlet pipe is connected to the water inlet of the instant electromagnetic water heater 40 or the instant electric water heater, and the water outlet of the instant electromagnetic water heater 40 or the instant electric water heater is connected to the other end of the first water inlet pipe 13; a Hall water flow sensor 19 electrically connected to the electrical control board is provided on the water inlet of the instant electromagnetic water heater 40 or the instant electric water heater.

In this embodiment, a mechanical water mixing thermostatic valve 50 is also included, the tap water inlet pipe is connected to the cold water inlet of the mechanical water mixing thermostatic valve 50, and the other end of the second water outlet pipe 3 is connected to the hot water inlet of the mechanical water mixing thermostatic valve 50.

In this embodiment, it also includes a water inlet tee 60, the tap water inlet pipe is connected to the water inlet of the water inlet tee 60, the first water outlet of the water inlet tee 60 is connected to the water inlet of the instant electromagnetic water heater 40 or the instant electric water heater, and the second water outlet of the water inlet tee 60 is connected to the cold water inlet of the mechanical water mixing thermostatic valve 50.

Of course, the mechanical water mixing thermostatic valve can also be replaced by an electronic thermostatic proportional valve.

In this embodiment, the second spirally wound tube heat exchanger 4 and/or the first spirally wound tube heat exchanger 9 are uniformly spaced uniformly distributed spirally wound tube heat exchangers or segmented spirally wound tube heat exchangers.

A control method for an electric water heater with two inner tanks connected in parallel for heating and in series for heat exchange comprises the following steps:

Step 1, preparation;

Pure water enters the first inner tank 30 through one end of the first pure water inlet pipe 14. When the pure water level in the first inner tank 30 reaches one end of the first pure water overflow pipe 7, the pure water level in the first inner tank 30 reaches equilibrium, and the second cavity is located above the pure water level in the first inner tank 30. At this time, the pure water in the first inner tank 30 becomes the first preheated water.

Pure water enters the second inner tank 20 through one end of the second pure water inlet pipe 12. When the pure water level in the second inner tank 20 reaches one end of the second pure water overflow pipe 2, the pure water level in the second inner tank 20 reaches equilibrium, and the first cavity is located above the pure water level in the second inner tank 20. At this time, the pure water in the second inner tank 20 becomes the second preheated water.

Step 2: preheating;

The maximum temperature of the first electronic thermometer 6 for controlling whether the first electric heater 10 works is set to T1, and the maximum temperature of the second electronic thermometer 1 for controlling whether the second electric heater 5 works is set to T2, and T2 is greater than or equal to T1;

The second electric heater 5 and the first electric heater 10 are respectively started through the electric control panel.

Of course, in practice, setting the maximum temperature T2 of the second electronic thermometer 1 higher than that of the first electronic thermometer 6T1 can further maximize the hot water energy conversion output rate.

When the temperature of the first preheated water sampled in time by the first electronic thermometer 6 reaches T1, the electric control board electrically connected to the first electronic thermometer 6 cuts off the working power of the first electric heater 10 by bipolar. When the temperature of the first preheated water sampled in time by the first electronic thermometer 6 is lower than T1, the electric control board electrically connected to the first electronic thermometer 6 turns on the working power of the first electric heater 10, and the first electric heater 10 resumes operation.

Bipolar cutting can completely separate water from electricity and improve the safety performance of the product.

When the temperature of the second preheated water sampled in time by the second electronic thermometer 1 reaches T2, the electric control board electrically connected to the second electronic thermometer 1 bipolarly cuts off the working power of the second electric heater 5; when the temperature of the second preheated water sampled in time by the second electronic thermometer 1 is lower than T2, the electric control board electrically connected to the second electronic thermometer 1 turns on the working power of the second electric heater 5, and the second electric heater 5 resumes operation;

Step 3, heat exchange;

When the Hall water flow sensor electrically connected to the electric control board and arranged on the water inlet of the instant electromagnetic water heater 40 or the instant electric water heater detects a water flow signal, the electric control board cuts off the working power of the second electric heater 5 and the first electric heater 10 in a bipolar manner, and the electric control board starts the working power of the instant electromagnetic water heater 40 or the instant electric water heater;

The tap water enters the instant electromagnetic water heater 40 or the instant electric water heater through the tap water inlet pipe, is heated and sterilized for the first time, and then becomes the first heated water.

The first heating water flows from the water outlet of the instant electromagnetic water heater 40 or the instant electric water heater to the other end of the first water inlet pipe 13, then enters the lowest point of the first spirally wound tube heat exchanger 9 from one end of the first water inlet pipe 13, then reaches the highest point of the first spirally wound tube heat exchanger 9, and finally flows out from the other end of the first water outlet pipe 8 connected to the highest point of the first spirally wound tube heat exchanger 9; the first heating water is heated by the first preheated water for the second time when flowing through the first spirally wound tube heat exchanger 9 to become the second heating water with a temperature of T3;

The second heating water enters the lowest point of the second spirally wound tube heat exchanger 4 through the other end of the first water outlet pipe 8, then reaches the highest point of the second spirally wound tube heat exchanger 4, and finally flows out from the other end of the second water outlet pipe 3 connected to the highest point of the second spirally wound tube heat exchanger 4; the second heating water is heated for the third time by the second preheated water when flowing through the second spirally wound tube heat exchanger 4 to become the third heating water with a temperature of T4;

The third heated water flows to the hot water inlet of the mechanical water mixing thermostatic valve 50 through the other end of the second water outlet pipe 3, and the tap water flows to the cold water inlet of the mechanical water mixing thermostatic valve 50 through the tap water inlet pipe. The user can obtain hot water with a suitable temperature by manually adjusting the opening of the mechanical water mixing thermostatic valve 50.

The control method of the electric water heater with double inner tanks for parallel heating and series heat exchange also includes the following steps:

Step 4: After the product is started, when the sampling temperature of the first preheated water remains at T1 for 5 to 30 seconds without changing, the electric control board cuts off the working power of the first electric heater 10 by bipolar; when the sampling temperature of the first preheated water remains at T2 for 5 to 30 seconds without changing, the electric control board cuts off the working power of the second electric heater 5 by bipolar. Then, the product is in a waiting state, waiting for the water flow signal to be detected from the Hall water flow sensor and transmitted to the electric control board.

When the product is started, the first preheated water and the second preheated water should be heated to the predetermined temperatures T1 and T2 respectively, and then the instant electromagnetic water heater 40 or the instant electric water heater will work. However, before the first preheated water and the second preheated water are heated to the predetermined temperatures T1 and T2 respectively, when the Hall water flow sensor electrically connected to the electric control board detects a water flow signal, the electric control board will immediately bipolarly cut off the working power of the first electric heater 10 and the second electric heater 5 to ensure user safety.

In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims (9)

1. A control method for an electric water heater with double inner tanks for parallel heating and series heat exchange, comprising a second inner tank (20) and a first inner tank (30), wherein a second spirally wound tube heat exchanger (4) is arranged in the second inner tank (20), one end of a second pure water inlet pipe (12) is inserted into the second inner tank (20) and opens at the bottom of the second inner tank (20), one end of a second pure water overflow pipe (2) is inserted into the second inner tank (20) and opens at the upper part of the second inner tank (20), one end of a second water inlet pipe (11) is inserted into the second inner tank (20) and communicates with the lowest part of the second spirally wound tube heat exchanger (4), and one end of a second water outlet pipe (3) is inserted into the second inner tank (20) and communicates with the highest part of the second spirally wound tube heat exchanger (4); The second inner tank (20) contains pure water as second preheated water, and the second spirally wound tube heat exchanger (4) is immersed in the second preheated water; A first spirally wound tube heat exchanger (9) is arranged in the first inner liner (30); one end of a first pure water inlet pipe (14) is inserted into the first inner liner (30) and opens at the bottom of the first inner liner (30); one end of a first pure water overflow pipe (7) is inserted into the first inner liner (30) and opens at the upper part of the first inner liner (30); one end of a first water inlet pipe (13) is inserted into the first inner liner (30) and communicates with the lowest part of the first spirally wound tube heat exchanger (9); and one end of a first water outlet pipe (8) is inserted into the first inner liner (30) and communicates with the highest part of the first spirally wound tube heat exchanger (9); The first inner tank (30) contains pure water as first preheated water, and the first spirally wound tube heat exchanger (9) is immersed in the first preheated water; The other end of the second water inlet pipe (11) is connected to the other end of the first water outlet pipe (8); A second cavity is provided between one end of the second pure water overflow pipe (2) and the top inner wall of the second inner container (20), and a first cavity is provided between one end of the first pure water overflow pipe (7) and the top inner wall of the first inner container (30); The following steps are involved: Step 1, preparation; Pure water enters the first inner tank (30) through one end of the first pure water inlet pipe (14); when the pure water level in the first inner tank (30) reaches one end of the first pure water overflow pipe (7), the pure water level in the first inner tank (30) reaches equilibrium, and the second cavity is located above the pure water level in the first inner tank (30); at this time, the pure water in the first inner tank (30) becomes first preheated water; Pure water enters the second inner tank (20) through one end of the second pure water inlet pipe (12). When the pure water level in the second inner tank (20) reaches one end of the second pure water overflow pipe (2), the pure water level in the second inner tank (20) reaches equilibrium, and the first cavity is located above the pure water level in the second inner tank (20). At this time, the pure water in the second inner tank (20) becomes second preheated water. Step 2: preheating; The maximum temperature of the first electronic thermometer (6) used to control whether the first electric heater (10) works is set to T1, and the maximum temperature of the second electronic thermometer (1) used to control whether the second electric heater (5) works is set to T2, and T2 is greater than or equal to T1; respectively starting the second electric heater (5) and the first electric heater (10) through the electric control panel; When the temperature of the first preheated water sampled in time by the first electronic thermometer (6) reaches T1, the electric control board electrically connected to the first electronic thermometer (6) cuts off the working power of the first electric heater (10) by bipolar, and when the temperature of the first preheated water sampled in time by the first electronic thermometer (6) is lower than T1, the electric control board electrically connected to the first electronic thermometer (6) turns on the working power of the first electric heater (10), and the first electric heater (10) starts working again; When the temperature of the second preheated water sampled in time by the second electronic thermometer (1) reaches T2, the electric control board electrically connected to the second electronic thermometer (1) bipolarly cuts off the working power of the second electric heater (5); when the temperature of the second preheated water sampled in time by the second electronic thermometer (1) is lower than T2, the electric control board electrically connected to the second electronic thermometer (1) turns on the working power of the second electric heater (5), and the second electric heater (5) starts working again; Step 3, heat exchange; When a Hall water flow sensor provided on the water inlet of the instant electromagnetic water heater (40) or the instant electric water heater and electrically connected to the electric control board detects a water flow signal, the electric control board bipolarly cuts off the working power of the second electric heater (5) and the first electric heater (10), and the electric control board starts the working power of the instant electromagnetic water heater (40) or the instant electric water heater; The tap water enters the instant electromagnetic water heater (40) or the instant electric water heater through the tap water inlet pipe, is heated and sterilized for the first time, and becomes the first heated water. The first heating water flows from the water outlet of the instant electromagnetic water heater (40) or the instant electric water heater to the other end of the first water inlet pipe (13), then enters the lowest point of the first spirally wound tube heat exchanger (9) from one end of the first water inlet pipe (13), then reaches the highest point of the first spirally wound tube heat exchanger (9), and finally flows out from the other end of the first water outlet pipe (8) connected to the highest point of the first spirally wound tube heat exchanger (9); the first heating water is heated for a second time by the first preheated water when flowing through the first spirally wound tube heat exchanger (9) to become second heating water with a temperature of T3; The second heating water enters the lowest point of the second spirally wound tube heat exchanger (4) through the other end of the first water outlet pipe (8), then reaches the highest point of the second spirally wound tube heat exchanger (4), and finally flows out from the other end of the second water outlet pipe (3) connected to the highest point of the second spirally wound tube heat exchanger (4); the second heating water is heated for the third time by the second preheated water when flowing through the second spirally wound tube heat exchanger (4) to become third heating water with a temperature of T4; The third heated water flows to the hot water inlet of the mechanical water mixing thermostatic valve (50) through the other end of the second water outlet pipe (3), and the tap water flows to the cold water inlet of the mechanical water mixing thermostatic valve (50) through the tap water inlet pipe. The user can obtain hot water of suitable temperature by manually adjusting the opening of the mechanical water mixing thermostatic valve (50). 2. The control method for an electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 1 is characterized in that a second electric heater (5) and a second liquid level sensor (17) which are respectively electrically connected to an electric control board of the electric water heater are arranged in the second inner tank (20), and a first electric heater (10) and a first liquid level sensor (18) which are respectively electrically connected to the electric control board are arranged in the first inner tank (30). 3. The control method of the electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 2, characterized in that the second electric heater (5) is arranged in parallel with the first electric heater (10). 4. The control method of the electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 2 is characterized in that a second electronic thermometer (1) electrically connected to the electric control board is arranged in the second inner tank (20), and the temperature sensing detection end of the second electronic thermometer (1) is inserted into the middle of the second inner tank (20); a first electronic thermometer (6) electrically connected to the electric control board is arranged in the first inner tank (30), and the temperature sensing detection end of the second electronic thermometer (6) is inserted into the middle of the first inner tank (30); wherein the preset temperature of the second electronic thermometer (1) is T2, and the preset temperature of the first electronic thermometer (6) is T1, and T2 is greater than or equal to T1. 5. The control method of the electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 4 is characterized in that it also includes an instant electromagnetic water heater (40) or an instant electric water heater electrically connected to the electric control board, the tap water inlet pipe is connected to the water inlet of the instant electromagnetic water heater (40) or the instant electric water heater, and the water outlet of the instant electromagnetic water heater (40) or the instant electric water heater is connected to the other end of the first water inlet pipe (13); a Hall water flow sensor (19) electrically connected to the electric control board is provided on the water inlet of the instant electromagnetic water heater (40) or the instant electric water heater. 6. The control method of the electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 5 is characterized in that it also includes a mechanical water mixing thermostatic valve (50), the tap water inlet pipe is connected to the cold water inlet of the mechanical water mixing thermostatic valve (50), and the other end of the second water outlet pipe (3) is connected to the hot water inlet of the mechanical water mixing thermostatic valve (50). 7. The control method for the electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 6 is characterized in that it also includes a water inlet tee (60), the tap water inlet pipe is connected to the water inlet of the water inlet tee (60), the first water outlet of the water inlet tee (60) is connected to the water inlet of the instant electromagnetic water heater (40) or the instant electric water heater, and the second water outlet of the water inlet tee (60) is connected to the cold water inlet of the mechanical water mixing thermostatic valve (50). 8. A control method for an electric water heater with double inner tanks for parallel heating and series heat exchange according to any one of claims 1 to 7, characterized in that the second spirally wound tube heat exchanger (4) and/or the first spirally wound tube heat exchanger (9) are uniformly spaced uniformly distributed spirally wound tube heat exchangers or segmented spirally wound tube heat exchangers. 9. The control method of the electric water heater with double inner tanks for parallel heating and series heat exchange according to claim 1, characterized in that the control method further comprises the following steps: Step 4, After the product is started, when the sampling temperature of the first preheated water remains at T1 without changing within 5 to 30 seconds, the electric control board bipolarly cuts off the working power of the first electric heater (10); when the sampling temperature of the first preheated water remains at T2 without changing within 5 to 30 seconds, the electric control board bipolarly cuts off the working power of the second electric heater (5).