CN103175304B - Electric water heater capable of automatically controlling temperature - Google Patents

Abstract

The present invention provides an electric water heater with automatic temperature control. The electric water heater includes a water heater liner. The liner has a multi-layer structure. The electric heater and the water heater liner include four side walls and a bottom wall. There are four electric heaters on the bottom wall and each side wall. As the heating temperature rises, the electric heaters are continuously activated and heated, and the temperature of the water is controlled according to the flow of water. The invention can control the heating power according to the water temperature to avoid the rapid thermal expansion of the inner tank, and meanwhile control the water temperature according to the water flow rate to ensure uniform heating temperature.

Description

An electric water heater with automatic temperature control

technical field

The invention belongs to the field of water heaters, in particular to an electric water heater with automatic temperature control.

Background technique

The heating power of the electric water heater commonly used in the family is relatively single at present, generally only has one kind of heating power, and the heating power will not change as the temperature of the water increases. Therefore, in this case, for a water heater with a relatively large heating power, once the heating is started, the temperature of the water will increase rapidly. It leads to rapid expansion of the inner tank, and multiple rapid expansions will easily lead to loosening of the combination between the inner tank and other shell materials, and will also reduce the frequency of use of the inner tank; some water heaters have low heating power, although they will heat up the water The speed is slow, thereby reducing the rapid thermal expansion of the inner tank, but the overall water heating speed is relatively slow, thus affecting the timeliness of use.

The invention aims at the deficiencies of the prior art and provides an electric water heater with automatic temperature control. The electric water heater can automatically select the appropriate heating power according to the water temperature of the water heater, so as to automatically supply a large amount of hot water in a short period of time.

Contents of the invention

The technical problem to be solved by the present invention is to provide an electric water heater with automatic temperature control, thereby effectively reducing the rapid expansion of the inner tank and ensuring timely supply of hot water.

In order to achieve the above object, the technical solution of the present invention is as follows: an electric water heater with automatic temperature control, the electric water heater includes a water heater liner, an electric heater, a cold water inlet pipe, a hot water outlet pipe, a temperature sensor, a water level controller, Flow controller, flow sensor and central controller, the inner liner has a four-layer structure, and each adjacent two layers are closely attached, the first layer from the inside to the outside is the inner paint layer, and the second layer is aluminum alloy layer, the third layer is a stainless steel layer, the fourth layer is an outer coating layer, and the hot water outlet pipe and the cold water inlet pipe are connected to the inner tank of the water heater. It is characterized in that the temperature sensor, water level controller, flow controller, The flow sensor, the electric heater and the central controller are communicatively connected, the inner tank includes four side walls and a bottom wall, four electric heaters are respectively arranged on the bottom wall and each side wall, respectively are the first electric heater, the second electric heater, the third electric heater and the fourth electric heater, which are used to heat the water in the water heater; The first electric heater described above starts heating, and the second electric heater, the third electric heater and the fourth electric heater do not start heating; when the temperature of the water reaches the first temperature, the water on the bottom wall and each side wall The second electric heater starts to start heating, the bottom wall and the first electric heater and the second electric heater on each side wall heat together, the bottom wall and the third electric heater on each side wall The heater and the fourth electric heater do not start heating; when the temperature reaches the second temperature, the third electric heater on the bottom wall and each side wall starts to start, and all the electric heaters on the bottom wall and each side wall The first electric heater, the second electric heater, and the third electric heater mentioned above heat the water together, and the fourth electric heater on the bottom wall and each side wall does not start heating; when the temperature reaches the fourth temperature , the fourth electric heater on the bottom wall and each side wall starts to start, and all the electric heaters on the bottom wall and each side wall heat the water together; the temperature sensor is set inside Inside the tank, it is used to measure the temperature of water. The flow sensor and the flow controller are arranged on the inlet pipe of the water heater, and the flow sensor is used to measure the flow of water flowing into the water heater inner tank; the flow controller is used to control the water heater The flow rate of the water on the inlet pipe, the water level controller is used to measure the water level of the inner tank of the water heater, and transmit the measurement result to the central controller, and the central controller controls the flow rate of the flow controller according to the measured water level and flow rate. The central controller includes an adjustment unit, which generates an adjustment signal for controlling the electric water heater and a signal for controlling the flow rate of the flow controller according to the temperature of the water measured by the temperature sensor.

There are multiple temperature sensors, wherein at least one temperature sensor is set at the hot water outlet position of the inner tank to measure the temperature of the outlet hot water, and at least one temperature sensor is set at the cold water inlet position of the inner tank to measure the inlet cold water temperature. The temperature of the water, wherein at least one temperature sensor is set at other positions of the inner tank of the water heater to measure the temperature of the water in the inner tank of the water heater. The adjustment signal of the device.

The electric heaters on each side wall are distributed along the height direction of the water heater liner, wherein from the bottom of the water heater liner upwards are the fourth electric heater, the second electric heater, the first electric heater, and the second electric heater. Three electric heaters.

The electric heaters on each side wall and/or are staggered along the height of the inner tank of the water heater.

The electric heaters on each side wall are distributed in a straight line along the height of the inner tank of the water heater. In the height direction, the second electric heater and the first electric heater are the first electric heater and the third electric heater. 0.8-0.9 times the distance, the distance between the fourth electric heater and the second electric heater is 0.7-0.75 times the distance between the second electric heater and the first electric heater.

The electric heaters on each side wall are distributed in a straight line along the height of the inner tank of the water heater, and the included angle between the straight line and the center line of the side wall is 30-45°.

The cold water inlet pipe is arranged near the position where the bottom wall and the side wall are connected on the bottom wall, and the electric heater on the bottom wall is distributed from near to far from the cold water inlet pipe as follows: the fourth electric heater, the second electric heater heater, the first electric heater and the third electric heater.

The mass percentages of the aluminum alloy components of the aluminum alloy layer are as follows: 6.0% Cu, 0.9% Mg, 0.6% Ag, 0.8% Mn, 0.13% Zr, 0.1% Ce, 0.10% Ti, 0.15% Si, and the rest is Al.

The power of the fourth electric heater on each side wall and/or bottom wall is greater than the power of the third electric heater, and the power of the third electric heater is greater than the power of the second electric heater, and the power of the second electric heater Greater than the power of the first electric heater.

The electric heater is composed of an electric heating alloy, and the mass percentage of the electric heating alloy is as follows Ni34%; Cr18%; Al5%; C0.05%; B0.006%; Co2%; W4%; Mo4%; Ti2%; Nb0.1 %; La0.2%; Ce0.2%; Fe balance.

The first temperature is 50 degrees Celsius, the second temperature is 60 degrees Celsius, and the third temperature is 75 degrees Celsius.

Compared with the prior art, the present invention has the following advantages:

1) By setting multiple electric heaters, only one of the electric heaters is turned on when the water heater starts to heat, thereby gradually increasing the temperature of the water, thus avoiding a rapid increase in the temperature of the water and avoiding the damage of the inner tank of the water heater. Rapid thermal expansion; when the water temperature reaches a certain level, the inner wall of the water heater has slowly expanded to a certain extent, so increasing the heating power at this time will not produce the thermal expansion speed of the water heater at the initial stage of heating, so increase life of the water heater.

2) By setting electric heaters on the four side walls and the bottom wall, the heated water temperature can be guaranteed to be uniform;

3) Set the electric heater in the height direction of the inner tank of the water heater, and place the electric heater that starts heating first in the middle of the three electric heaters, so as to reduce the heat generated by the electric heater that starts first on the bottom wall of the inner tank. rising phenomenon.

4) Through the water level controller, flow controller and flow sensor, the control of the flow rate entering the water heater is realized.

5) By setting a plurality of temperature sensors to ensure the accuracy of the measured water temperature.

6) Through the setting of electric heater spacing and heating power, uniform heating of water is realized.

7) The high heat resistance and high temperature tensile strength of the alloy layer of the inner tank are improved by rationally distributing the mass percentage of the aluminum alloy component of the aluminum alloy layer.

8) By setting the components of the electrothermal alloy, the electrothermal alloy has high oxidation resistance and corrosion resistance.

Description of drawings

Figure 1 is a structural diagram of the inner tank of the water heater

Figure 2 is the overall appearance of the water heater

Fig. 3 is the schematic diagram of electric water heater work of the present invention

Figure 4 is one of the distribution diagrams of the electric heater on the side wall

Figure 5 is another distribution diagram of the electric heater on the side wall

The reference signs are as follows: 1 central controller, 2 the first electric heater of the first side wall, 3 the second electric heater of the first side wall, 4 the third electric heater of the first side wall, 5 the first side The fourth electric heater of the wall, 6 cold water inlet pipe, 7 hot water outlet pipe, 8 temperature sensor, 9 temperature sensor, 10 temperature sensor, 11 flow sensor, 12 flow controller, 13 water heater liner, 14 bottom wall of the fourth Three electric heaters, 15 the first electric heater of the bottom wall, 16 the second electric heater of the bottom wall, 17 the fourth electric heater of the bottom wall, 18 the first electric heater of the second side wall, 19 the second The second electric heater of the side wall, the third electric heater of the 20 second side wall, the fourth electric heater of the 21 second side wall, the first layer of 22 inner tank, the second layer of 23 inner tank, 24 The third layer of inner tank, the fourth layer of 25 inner tank, 26 shell

Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

First of all, please refer to Fig. 1, an electric water heater with automatic temperature control, the electric water heater includes a water heater liner 13 and an outer shell 26, a cold water inlet pipe 6 is arranged at the lower part of the water heater, and a hot water outlet pipe 7 is arranged on one side of the upper part, and the cold water Enter the water heater liner 13 through the cold water inlet pipe 6, then heat in the water heater liner 13, and then flow out through the hot water outlet pipe 7.

FIG. 2 shows a schematic diagram of the inner tank 13 of the water heater. The inner tank 13 of the water heater is divided into four layers, and every adjacent two layers are closely bonded. From the inside to the outside, there are respectively an inner coating layer 22, an aluminum alloy layer 23, a stainless steel layer 24 and an outer coating layer 25. The inner tank 13 of the water heater adopts the The above structure, the first layer is the inner coating layer, which can avoid corrosion, the second layer is the aluminum alloy layer, which makes the heat transfer uniform and the cooking effect is good, and the third layer is the stainless steel layer, so that the outer surface of the inner tank is not only beautiful, but also It makes the heat transfer of the inner tank faster, and the fourth layer is the outer paint layer, which can protect the copper layer from corrosion.

The side wall and the bottom wall of the liner 13 shown in Fig. 2 are obtuse angles greater than 90°. Of course, the side walls and the bottom wall of the liner are not limited to the form of the accompanying drawings, and the liner and the side wall can be at an angle of 90°. The liner can be in the shape of a cube and is composed of four mutually perpendicular side walls and a bottom wall.

The material in the inner tank 13 is not limited to the materials described above, those skilled in the art can make a reasonable choice, but for the selection of the material of the four-layer structure of the inner tank, the thermal expansion coefficient of the four-layer structure from the inside to the outside is required Gradually increasing, that is to say, the innermost layer has the lowest coefficient of thermal expansion, the second layer is next, the third layer is larger than the second layer but smaller than the fourth layer, and the fourth layer is the largest. The reason for this setting is that during the heating process, the first layer is heated and expanded first, and then the second layer, the third layer, and the fourth layer are heated and expanded in turn, so the expansion times of the four layers increase in sequence to ensure expansion. The rate is basically consistent to ensure the tightness and stability of the connection of each layer.

As shown in Figure 3, the electric water heater includes an electric heater, a temperature sensor and a central controller 1, wherein the hot water outlet pipe 7 and the cold water inlet pipe 6 are connected to the water heater liner 13. The temperature sensors 8-10, electric The heaters 2-5, 14-17, 18-21 are communicatively connected with the central controller 1, and the inner tank 13 includes four side walls (only two side walls are shown in Fig. 3 ) and a bottom wall, four electric heaters are respectively arranged on the bottom wall and each side wall. As shown in Figure 3, the first electric heater 2, the second electric heater 3, the third electric heater 4 and the fourth electric heater 5 are respectively on the first side wall of the water heater liner in Figure 3, with On the second side wall of the water heater liner in Fig. 3 are respectively the first electric heater 18, the second electric heater 19, the third electric heater 20 and the fourth electric heater 21, while the two sides of the water heater liner The setting of the electric heaters of the two outer side walls is the same as that of the first side wall and the second side wall, and four electric heaters are respectively arranged; the bottom wall of the inner liner 13 is provided with four electric heaters, respectively Be the 3rd electric heater 14, the first electric heater 15, the second electric heater 16 and the 4th electric heater 17, the electric heater of above-mentioned setting is used for heating the water in the water heater; When starting heating, The first electric heaters 2, 18, 15 (comprising the first electric heaters on the two side walls not shown) on the bottom wall and each side wall start heating, the second electric heater, the first electric heater The third electric heater and the fourth electric heater do not start heating; when the temperature of the water reaches the first temperature, the second electric heater on the bottom wall and each side wall starts to start heating, and the bottom wall and each side wall start heating. The first electric heater and the second electric heater on the side wall are heated together, and the third electric heater and the fourth electric heater on the bottom wall and each side wall do not start heating; when the temperature reaches the second temperature, the third electric heater on the bottom wall and each side wall starts to start, and the first electric heater, the second electric heater, and the third electric heater on the bottom wall and each side wall The heaters heat the water together, and the fourth electric heater on the bottom wall and each side wall does not start heating; when the temperature reaches the third temperature, the fourth electric heater on the bottom wall and each side wall The heater starts to start, and all the electric heaters on the bottom wall and each side wall heat the water together; the central controller 1 includes a regulating unit, and the regulating unit is based on the temperature of the water measured by the temperature sensor , generating an adjustment signal for controlling the electric water heater.

In the actual heating process, as long as the temperature of the water is lower than the first temperature, only the first electric heaters on the bottom wall and the four side walls are activated, and if the temperature of the water is between the first temperature and the second temperature, Then start the first electric heater and the second electric heater of the bottom wall and the four side walls at the same time, if the temperature of the water is between the second temperature and the third temperature, then start the electric heaters of the bottom wall and the four side walls at the same time The first electric heater, the second electric heater and the third electric heater, when the temperature of the water reaches or exceeds the third temperature, all the electric heaters are started simultaneously for heating.

There are a plurality of temperature sensors, all of which are arranged in the liner 5 . As shown in Figure 3, one of the temperature sensors 8 is set at the hot water outlet position of the inner tank to measure the hot water temperature of the outlet hot water, and one of the temperature sensors 9 is set at the cold water inlet position of the inner tank to measure the temperature of the inlet water. The water temperature of the cold water, wherein at least one temperature sensor 10 is arranged at other positions of the water heater liner, is used for measuring the temperature of the water in the water heater liner 10, such as being arranged at the bottom of the liner 5 as shown in Figure 3 . The adjustment unit generates an adjustment signal for controlling the electric heater through an average value of temperatures measured by a plurality of temperature sensors.

Although the number of temperature sensors in Figure 3 is three, in fact, the number of temperature sensors is not limited to three, for example, the number of sensors at the hot water outlet position of the water heater, the cold water inlet position and other positions can be more than two . The measurement accuracy of the water temperature can be increased by setting multiple temperature sensors.

Of course, those skilled in the art can also choose to arrange the temperature sensor on the hot water inlet pipe and/or the cold water outlet pipe as required, and calculate the average value of the measured temperature together with the temperature sensor arranged on the inner tank.

As shown in Figure 3, the electric heaters on the first side wall are distributed along the height direction of the water heater inner tank, wherein from the bottom of the water heater inner tank upwards are the fourth electric heater 5, the second electric heater 3, The first electric heater 2, the third electric heater 4. The setting of electric heaters on other side walls is the same as that of the first side wall.

The electric heaters on each side wall are distributed in a straight line along the height of the inner tank of the water heater. In the height direction, the second electric heater 3 and the first electric heater 2 are the first electric heater 2 and the third electric heater. 0.8-0.9 times the distance between the electric heater 4 and the distance between the fourth electric heater 5 and the second electric heater 3 is 0.7-0.75 times the distance between the second electric heater 3 and the first electric heater 2 . The setting of electric heaters on other side walls is the same as that of the first side wall.

The power of the fourth electric heater 5 is greater than the power of the third electric heater 4, the power of the third electric heater 4 is greater than the power of the second electric heater 3, and the power of the second electric heater 3 is greater than the first electric heater 2 power. The setting of electric heaters on other side walls is the same as that of the first side wall.

The cold water inlet 6 is arranged near the position where the bottom wall and the side wall are connected on the bottom wall, and the electric heater on the bottom wall is distributed from near to far from the cold water inlet pipe 6 as follows: the fourth electric heater 17, the second Electric heater 16 , first electric heater 15 and third electric heater 14 .

On the bottom wall, the power of the fourth electric heater 17 is greater than the power of the third electric heater 14, the power of the third electric heater 14 is greater than the power of the second electric heater 16, and the power of the second electric heater 16 is greater than The power of the first electric heater 15.

Through the above-mentioned setting of position and power, the balance of water heating can be improved, and the consistency of temperature increase of each wall surface can be ensured.

Described electric water heater also comprises water level controller (Fig. 3 is not shown), flow controller 12, flow sensor 11, and water level controller, flow controller 12, flow sensor 11 are connected with central controller 1 communication, and flow sensor 11 And the flow controller 12 is arranged on the water heater inlet pipe 6, and the flow sensor 11 is used to measure the flow of water flowing into the water heater inner tank 5; the flow controller 12 is used to control the flow rate of the water on the water heater inlet pipe 6 , the water level controller is used to measure the water level of the inner tank of the water heater, and transmit the measurement result to the central controller 1, and the central controller 1 controls the flow rate of the flow controller 12 according to the measured water level and flow rate, and the central controller 1 can also The flow rate of the flow controller 12 is controlled according to the water temperature and flow rate. For example, if the water temperature in the water tank exceeds the user's demand, the water temperature can be reduced by setting the increase of the water flow rate. Similarly, if the water temperature in the water tank is lower than the user's demand, the water flow rate can be reduced to ensure the water flow quickly. heating. User's needs can be set through a user interface (not shown). If the water level drops, then increase the flow of water entering the inner tank by controlling the increased flow rate, and if the water level is too high, reduce or avoid the flow of water entering the inner channel by reducing or stopping the flow rate of water.

As shown in Figure 4, the electric heaters on the first side wall are staggered and distributed along the height of the inner tank of the water heater. Of course, the electric heaters on each side wall and bottom wall can adopt the staggered distribution as shown in Figure 4,

The electric heaters on each of the side walls are distributed in a straight line along the height of the water heater liner, as shown in Figure 5, the angle between the straight line and the center line of the side wall is 30-45 ° (shown in Figure 5 the angle formed by the two dotted lines). Of course, the electric heaters on the bottom wall can all adopt the staggered distribution as shown in FIG. 5 .

Through the position setting of the above-mentioned electric heater, the balance of heating of the water can be improved, and the consistency of the temperature increase of each wall surface can be ensured.

In practical applications, an anti-drying device can also be provided to ensure that the electric heaters for heating are all immersed in water. If the electric heater is not immersed in water, the electric heater will automatically stop heating to prevent dry burning. Wait for the water level to rise and submerge the electric heater before heating.

The mass percentages of the aluminum alloy components of the aluminum alloy layer are as follows: 6.0% Cu, 0.9% Mg, 0.6% Ag, 0.8% Mn, 0.13% Zr, 0.1% Ce, 0.10% Ti, 0.15% Si, and the rest is Al.

The manufacturing method of aluminum alloy is: vacuum metallurgical smelting, argon protection casting into a round billet, after homogenization treatment at 600 °C, hot extrusion at 400 °C into rods, and then after solid solution quenching at 580 °C, in 200°C for artificial aging treatment. Tensile strength σb of the alloy: room temperature ≥ 550MPa, 200°C ≥ 440MPa, 300°C ≥ -230MPa.

The electric heater is composed of an electric heating alloy, and the mass percentage of the electric heating alloy is as follows Ni34%; Cr18%; Al5%; C0.05%; B0.006%; Co2%; W4%; Mo4%; Ti2%; Nb0.1 %; La0.2%; Ce0.2%; Fe balance.

The manufacturing method of the electrothermal alloy is: melting and pouring into an ingot according to the composition of the electrothermal alloy in a vacuum induction furnace, then hot forging the alloy ingot into a bar at 1200°C-900°C, and hot rolling into a plate at 1200°C-900°C , and then cold-drawn into wires of different specifications at room temperature.

In order to replace the widely used NiCr-based Cr20Ni80 alloy, a low-cost electric heating alloy has been manufactured. The oxidation resistance of the alloy is compared with that of Cr20Ni80 as follows:

Although the present invention has been disclosed above with preferred embodiments, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (1)

1. An electric water heater with automatic temperature control, the electric water heater comprises a water heater liner, an electric heater, a cold water inlet pipe, a hot water outlet pipe, a temperature sensor, a water level controller, a flow controller, a flow sensor and a central controller , the inner tank includes a four-layer structure, and each adjacent two layers are closely bonded. The first layer from the inside to the outside is an inner paint layer, the second layer is an aluminum alloy layer, the third layer is a stainless steel layer, and the second layer is a stainless steel layer. The fourth layer is the outer paint layer, and the hot water outlet pipe and the cold water inlet pipe are connected to the inner tank of the water heater. It is characterized in that the temperature sensor, water level controller, flow controller, flow sensor, electric heater and the central control The inner tank includes four side walls and a bottom wall, and each of the bottom wall and each side wall is provided with four electric heaters, which are respectively the first electric heater , the second electric heater, the third electric heater and the fourth electric heater are used to heat the water in the water heater; when starting to heat, the first electric heater on the bottom wall and each side wall The heater starts heating, the second electric heater, the third electric heater and the fourth electric heater do not start heating; when the temperature of the water reaches the first temperature, the second electric heater on the bottom wall and each side wall The heater starts heating, the bottom wall and the first electric heater and the second electric heater on each side wall heat together, the third electric heater and the fourth electric heater on the bottom wall and each side wall The heater does not start heating; when the temperature reaches the second temperature, the third electric heater on the bottom wall and each side wall starts to start, and the first electric heater on the bottom wall and each side wall The heater, the second electric heater, and the third electric heater heat the water together, and the fourth electric heater on the bottom wall and each side wall does not start heating; when the temperature reaches the fourth temperature, the bottom wall and each side wall The fourth electric heater on the side wall starts to start, and all the electric heaters on the bottom wall and each side wall heat the water together; the temperature sensor is arranged in the inner tank for measuring The temperature of the water, the flow sensor and the flow controller are arranged on the inlet pipe of the water heater, the flow sensor is used to measure the flow of water flowing into the inner tank of the water heater; the flow controller is used to control the flow rate of the water on the inlet pipe of the water heater flow rate, the water level controller is used to measure the water level of the inner tank of the water heater, the central controller includes an adjustment unit, and the adjustment unit generates an adjustment signal for controlling the electric heater according to the temperature of the water measured by the temperature sensor; In order to ensure that the water level of the inner tank maintains a certain height, the central controller controls the flow rate of the flow controller according to the measured water level and flow rate; in order to ensure that the temperature of the water in the inner tank reaches the predetermined temperature, the central controller can control the flow rate according to the water temperature and flow rate The flow rate of the controller; the temperature sensor is multiple, wherein at least one temperature sensor is set at the hot water outlet position of the inner tank to measure the temperature of the outlet hot water, and at least one temperature sensor is set at the cold water inlet position of the inner tank, It is used to measure the water temperature of the inlet cold water, wherein at least one temperature sensor is arranged at other positions of the inner tank of the water heater, and is used to measure the temperature of the water in the inner tank of the water heater. The average value of the temperature measured by the sensor is used to generate an adjustment signal for controlling the electric water heater; the electric heaters on each side wall are distributed along the height direction of the water heater inner tank, wherein from the bottom of the water heater inner tank to the top is The fourth electric heater, the second electric heater, the first electric heater, and the third electric heater, the electric heaters on each side wall are staggered along the height of the water heater liner.

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