A dual-tank water heater and a heating control method thereof

Abstract

The application discloses a double-tank water heater and a heating control method thereof. The water heater can be started according to the flow rate. When the flow rate is greater than Q1, the first heating tube and the second heating tube are directly started to heat the water in the first inner tank and the second inner tank, i.e. the water in the first inner tank and the second inner tank is heated at full power. If the flow rate of the water is very large, the water in the second inner tank is rapidly cooled, and then the second heating tube and the third heating tube are switched to heat the water in the second inner tank, so that the temperature of the water in the first inner tank is rapidly reduced, the temperature of the water in the second inner tank is rapidly increased, and the temperature of the outlet water is increased. In this way, the shortcomings of the storage water heater, such as long-term heat preservation and heating of the water in the water tank, large volume, large power consumption and low energy efficiency, are overcome. The direct-heating electric water heater does not have a water tank, and the power is particularly large. The application has the advantages of proper volume, low power consumption and low total power.

Description

TECHNICAL FIELD

[0001] The present application relates to a double-tank water heater, and a heating control method of the double-tank water heater. BACKGROUND

[0002] Common electric water heaters are roughly divided into large-tank storage type and direct heating type. The large-tank storage type electric water heater is provided with a water tank, and a heater is used to heat and keep warm the water in the water tank for a long time. The water tank is large in size, high in power consumption, and low in energy efficiency. The direct heating type electric water heater cancels the water tank, and uses a high-power (usually more than 6 kW) heater. The water heater is fast in temperature rise and high in energy efficiency. However, such high power greatly burdens the power supply circuit of a general household, and the phenomenon of tripping is prone to occur. In order to reduce the maximum heating power and improve the energy efficiency, the present application arises at the historic moment. SUMMARY

[0003] In view of the respective defects of the large-tank storage type and the direct heating type electric water heaters in the prior art, the present application solves the technical problems by using the technical scheme of a double-tank water heater, which comprises a first inner tank, a second inner tank, a water inlet pipe, a water outlet pipe, a connecting water pipe, a first heating pipe, a second heating pipe, a third heating pipe, a first temperature sensor, a second temperature sensor, a flow sensor, and a controller. The first inner tank is used to store water to be heated. The second inner tank is used to store water to be heated. The water inlet pipe extends into the first inner tank. The water outlet pipe extends into the second inner tank. The connecting water pipe is connected between the first inner tank and the second inner tank, so that the inner cavities of the first inner tank and the second inner tank are communicated. The first heating pipe is used to heat the water stored in the first inner tank. The second heating pipe is used to heat the water stored in the second inner tank. The third heating pipe is used to heat the water stored in the second inner tank. The first temperature sensor is used to detect the temperature of the water in the first inner tank. The second temperature sensor is used to detect the temperature of the water in the second inner tank. The flow sensor is connected to the water inlet pipe and / or the water outlet pipe, and is used to detect the flow of the water passing through the first inner tank and the second inner tank. The controller is electrically connected to the first heating pipe, the second heating pipe, and the third heating pipe to control the start or stop of the first heating pipe, the second heating pipe, and the third heating pipe. The controller is also connected to the first temperature sensor, the second temperature sensor, and the flow sensor.

[0004] The double-tank water heater described above is provided with two groups of connecting water pipes between the first inner tank and the second inner tank, and the two groups of connecting water pipes are connected in parallel between the first inner tank and the second inner tank.

[0005] The double-tank water heater described above is provided with two groups of connecting water pipes between the first inner tank and the second inner tank, and the two groups of connecting water pipes are connected in parallel between the first inner tank and the second inner tank.

[0006] A double-tank water heater as described above, wherein the volume of the first inner tank is 8L-25L; and the volume of the second inner tank is 8L-25L.

[0007] A double-tank water heater as described above, wherein the first inner tank is connected with a drain pipe.

[0008] A double-tank water heater as described above, wherein the power of the first heating tube is P1, the power of the second heating tube is P2, and the power of the third heating tube is P3, wherein: P1+P2=P2+P3, and P1>P2.

[0009] A heating control method of a double-tank water heater, comprising the following control steps:

[0010] Step S1, initial water filling and power on: after cold water fills the first inner tank and the second inner tank through the water inlet pipe, the power is started, the controller controls the first heating tube to start, the second heating tube to start, and the third heating tube to stop, the controller receives the temperature T1i measured by the first temperature sensor at the current time and the temperature T2i measured by the second temperature sensor at the current time, and when T1i and T2i are equal to the set value T1, the controller controls the first heating tube, the second heating tube and the third heating tube to stop working;

[0011] Step S2, the controller receives the flow rate Qi measured by the flow sensor at the current time, and judges the size relationship between Qi and the set value Q1;

[0012] If Qi≥Q1, step S3 is entered;

[0013] If 0<Qi<Q1, the size relationship between the current time T1i, T2i and the set value T1 is judged;

[0014] If T1i=T2i=T1, step S2 is returned to;

[0015] If T1i

[0016] Step S3, the controller controls the first heating tube to start, the second heating tube to start, and the third heating tube to stop, and judges the size relationship between the current time T1i, T2i and the set value T1 and the set value T2;

[0017] If T1i=T2i=T1, the controller controls the first heating tube, the second heating tube and the third heating tube to stop working, and returns to step S2;

[0018] If T2≤T2i

[0019] If T2i

[0020] Step S4, the controller controls the first heating tube to stop, the second heating tube to start, the third heating tube to start, and judges the size relation between the current time T2i and the setting value T1 and the setting value T2;

[0021] If T2i < T2, return to step S4;

[0022] If T2 ≤ T2i < T1, return to step S3.

[0023] The heating control method of the double-tank water heater as described above, the range of T1 is 40℃-80℃.

[0024] The heating control method of the double-tank water heater as described above, T2 = T1-Tk, wherein the value of Tk is 5℃-8℃.

[0025] The heating control method of the double-tank water heater as described above, 0.9L / min ≤ Q1 ≤ 1.1L / min.

[0026] The present application has the following beneficial effects:

[0027] 1. The water heater of the present application can be started according to the flow rate, and when the flow rate is greater than Q1, the first heating tube and the second heating tube are directly started to heat the water in the first inner tank and the second inner tank, i.e. the total power (P1+P2) is used to heat the water in the first inner tank and the second inner tank; if the flow rate of the water used is very large, the water in the second inner tank is rapidly cooled, and then the second heating tube and the third heating tube are switched to heat the water in the second inner tank, i.e. the total power (P2+P3) is used to heat the water in the second inner tank, and the first inner tank and the second inner tank are connected through the connecting water pipe, so that the temperature of the water in the second inner tank is rapidly increased, and the temperature of the outlet water is further increased. In this way, the disadvantages of the storage-type water heater, such as large volume, high power consumption and low energy efficiency, are overcome; the defect of the direct-heating type electric water heater, i.e. no water tank and high power, is also overcome; and the water heater has the advantages of appropriate volume, low power consumption and low total power.

[0028] The present application will be further described below in conjunction with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a structure schematic view of the double-tank water heater of the embodiment 1 of the present application;

[0030] Figure 2 It is a perspective sectional view schematic view of the double-tank water heater of the embodiment 1 of the present application;

[0031] Figure 3 It is an exploded schematic view of the double-tank water heater of the embodiment 1 of the present application;

[0032] Figure 4This is a schematic diagram of the structure of the dual-tank water heater according to Embodiment 2 of the present invention;

[0033] Figure 5 This is a three-dimensional sectional view of the dual-tank water heater according to Embodiment 2 of the present invention;

[0034] Figure 6 This is a circuit block diagram of the dual-tank water heater of the present invention. Detailed Implementation

[0035] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] like Figures 1 to 4 as well as Figure 6 As shown, a dual-tank water heater according to this embodiment includes: a first inner tank 1, a second inner tank 2, an inlet pipe 11, an outlet pipe 21, a connecting pipe 22, a first heating element 31, a second heating element 32, a third heating element 33, a first temperature sensor 41, a second temperature sensor 42, a flow sensor 5, and a controller 6. The first inner tank 1 is used to store water to be heated; the second inner tank 2 is used to store water to be heated; the inlet pipe 11 extends into the first inner tank 1; the outlet pipe 21 extends into the second inner tank 2; the connecting pipe 22 connects the first inner tank 1 and the second inner tank 2, making the inner cavities of the first inner tank 1 and the second inner tank 2 communicate; the first heating element 31 is used to heat the water stored in the first inner tank 1; the second heating element 32... The second inner tank 2 is used to heat the water stored in the second inner tank 2; the third heating element 33 is used to heat the water stored in the second inner tank 2; the first temperature sensor 41 is used to detect the temperature of the water in the first inner tank 1; the second temperature sensor 42 is used to detect the temperature of the water in the second inner tank 2; the flow sensor 5 is connected to the inlet pipe 11 and / or the outlet pipe 21 to detect the flow rate of water passing through the first inner tank 1 and the second inner tank 2; the controller 6 is electrically connected to the first heating element 31, the second heating element 32 and the third heating element 33 to control the start or stop of the first heating element 31, the second heating element 32 and the third heating element 33, and the controller 6 is also connected to the first temperature sensor 41, the second temperature sensor 42 and the flow sensor 5. The dual-tank water heater of the present invention overcomes the disadvantages of storage-type water heaters, which require long-term heat preservation of the water in the tank, resulting in large size, high power consumption and low energy efficiency; it also overcomes the disadvantages of direct-heating electric water heaters, which have no tank and extremely high power consumption; it has the advantages of appropriate size, low power consumption and low total power.

[0037] In the embodiment, two groups of connecting water pipes 22 are arranged between the first inner container 1 and the second inner container 2, and the two groups of connecting water pipes 22 are connected in parallel between the first inner container 1 and the second inner container 2. The inner diameter of the connecting water pipe 22 is 40mm-50mm. The two groups of connecting water pipes 22 can ensure that the first inner container can flow into the second inner container, and can also make the first inner container and the second inner container relatively independent, so that the heat exchange between the first inner container and the second inner container is not too fast, and the full power is concentrated on the second inner container for heating, so that the water temperature of the second inner container is higher than that of the second inner container.

[0038] In the embodiment, the volume of the first inner container 1 is 8L-25L; the volume of the second inner container 2 is 8L-25L; therefore the first inner container and the second inner container can store 20L-36L of hot water, so that the total heating power does not need to be as large as that of the direct heating type electric water heater to meet the use requirements.

[0039] In order to facilitate cleaning, a drain pipe 13 is connected to the first inner container 1.

[0040] In the embodiment, the power of the first heating pipe 31 is P1, the power of the second heating pipe 32 is P2, and the power of the third heating pipe 33 is P3, wherein: P1+P2=P2+P3, P1>P2. Because the first inner container 1 is filled with cold water, and the water in the second inner container 2 flows from the first inner container 1, the water temperature of the first inner container 1 decreases faster than that of the second inner container 2, so in order to balance, the power of the first heating pipe 31 is greater than that of the second heating pipe 32.

[0041] As shown in Figure 4 and Figure 5 The first inner container and the second inner container in Embodiment 1 are vertically placed, and compared with Embodiment 1, the first inner container and the second inner container in Embodiment 2 are horizontally placed.

[0042] The embodiment provides a heating control method of the double-tank water heater.

[0043] Step S1, initial water filling and power on: after the cold water fills the first inner container 1 and the second inner container 2 from the water inlet pipe 11, the power is started, the controller 6 controls the first heating pipe 31 to start, the second heating pipe 32 to start, and the third heating pipe 33 to stop, and the controller 6 receives the temperature T1i measured at the current time by the first temperature sensor 41 and the temperature T2i measured at the current time by the second temperature sensor 42, and when T1i, T2i are equal to the set value T1, the controller 6 controls the first heating pipe 31, the second heating pipe 32 and the third heating pipe 33 to stop working;

[0044] Step S2, the controller 6 receives the flow rate Qi measured at the current time by the flow sensor 5, and judges the size relationship between Qi and the set value Q1;

[0045] If Qi≥Q1, go to step S3;

[0046] If 0<Qi<Q1, judge the size relation between the current time T1i, T2i and the set value T1;

[0047] If T1i=T2i=T1, return to step S2;

[0048] If T1i

[0049] Step S3, the controller 6 controls the first heating tube 31 to start, the second heating tube 32 to start, the third heating tube 33 to stop, and judges the size relation between the current time T1i, T2i and the set value T1, the set value T2;

[0050] If T1i=T2i=T1, the controller 6 controls the first heating tube 31, the second heating tube 32 and the third heating tube 33 to stop working, and returns to step S2;

[0051] If T2≤T2i

[0052] If T2i

[0053] Step S4, the controller 6 controls the first heating tube 31 to stop, the second heating tube 32 to start, the third heating tube 33 to start, and judges the size relation between the current time T2i and the set value T1, the set value T2;

[0054] If T2i

[0055] If T2≤T2i

[0056] Now the working principle of the present application is described:

[0057] (1) When the water is first filled and the power is turned on, the first inner container 1 and the second inner container 2 are heated to the set value T1 through the first heating tube 31 and the second heating tube 32, and the range of T1 is 40℃-80℃. T1 can be set according to the actual situation. The first heating tube 31, the second heating tube 32 and the third heating tube 33 are closed, and the hot water in the first inner container 1 and the second inner container 2 is in a heat preservation state. Even if the hot water in the first inner container 1 and the second inner container 2 cools down, it will not be heated. This overcomes the shortcomings of the storage water heater, such as large volume, high power consumption and low energy efficiency, because the heater of the storage water heater is used for heat preservation and heating of the water in the water tank for a long time.

[0058] (2) Step S2 mainly controls the heating through the data detected by the flow sensor 5. Here, there are two cases:

[0059] Case one, when the flow is small, i.e. 0 < Qi < Q1, where 0.9L / min < Q1 < 1.1L / min, the temperature is detected at the current time T1i, T2i and the set value T1, if the temperature does not drop, i.e. T1i = T2i = T1, then return to step S2; if the temperature of the first inner container 1 or the second inner container 2 drops, i.e. T1i < T1 or T2i < T1, then enter step S3.

[0060] Case two, when the flow is large, i.e. Qi > Q1, then enter step S3; this can improve the heating efficiency and reduce time waste.

[0061] (3) Step S3, the first heating tube 31 and the second heating tube 32 are started to heat the water in the first inner container 1 and the second inner container 2; and the water temperature of the first inner container 1 and the second inner container 2 is detected to control the heating, which is divided into three cases:

[0062] Case one, if the temperature is heated to the set temperature T1, i.e. T1i = T2i = T1, then the first heating tube 31, the second heating tube 32 and the third heating tube 33 are all stopped, and return to step S2; this case corresponds to the first heating tube 31 and the second heating tube 32 which can quickly heat the water temperature to the set temperature T1 (water flow is relatively small);

[0063] Case two, if the water temperature of the second inner container is between T2 and T1, i.e. T2 < T2i < T1, then return to step S3; this case corresponds to the first heating tube 31 and the second heating tube 32 which can heat the water temperature to between T2 and T1, which can maintain a high water temperature (water flow is moderate);

[0064] Case three, if the water temperature of the second inner container is lower than T2, i.e. T2i < T2, then enter step S4; this case corresponds to the first heating tube 31 and the second heating tube 32 which cannot heat the water temperature to between T2 and T1, which cannot maintain the set water temperature (water flow is large);

[0065] (4) Step S4, the second heating tube 32 and the third heating tube 33 are started to heat the water in the second inner container 2, so that the water temperature in the second inner container 2 rises rapidly, and the water temperature of the second inner container 2 is detected to control the heating, which is divided into two cases:

[0066] Case one, if the water temperature of the second inner container is still lower than T2, i.e. T2i < T2, then return to step S4;

[0067] Case two, if the water temperature of the second inner container is between T2 and T1, i.e. T2 < T2i < T1, then return to step S3.

[0068] In the present application, T2=T1-Tk, wherein the value of Tk is 5-8℃.

[0069] Suppose P1=P3=4KW, P2=1.5KW, i.e. the maximum power of heating is P1+P2=5.5kw or P2+P3=5.5kw. In simple terms, the water heater of the present application can be started according to the flow, and when the flow is greater than Q1, the first heating tube and the second heating tube are directly started to heat the water in the first inner container and the second inner container, i.e. the full power (P1+P2) is used to heat the water in the first inner container and the second inner container; if the flow of water is very large, the water in the second inner container is rapidly cooled, and the second heating tube and the third heating tube are switched on to heat the water in the second inner container, i.e. the full power (P2+P3) is used to heat the water in the second inner container, and the first inner container and the second inner container are connected through the connecting water pipe, so that the temperature of the water in the second inner container is rapidly increased, thereby increasing the temperature of the outlet water. In this way, the disadvantages of the storage water heater, such as large volume, high power consumption and low energy efficiency, are overcome; the straight heating type electric water heater is also improved, which has the defect of no water tank and high power; and the present application has the advantages of appropriate volume, low power consumption and low total power.

[0070] The above is only to further illustrate the technical content of the present application by way of examples, so that the reader can more easily understand, but it does not mean that the embodiments of the present application are limited to this, any technical extension or re-creation made according to the present application is protected by the present application. The protection scope of the present application is subject to the claims.

Claims

1. A heating control method of a double-tank water heater, the double-tank water heater comprising: a first inner tank (1) for storing water to be heated; a second inner tank (2) for storing water to be heated; a water inlet pipe (11) extending into the first inner tank (1); a water outlet pipe (21) extending into the second inner tank (2); a connecting water pipe (22) connecting between the first inner tank (1) and the second inner tank (2) to make the inner cavities of the first inner tank (1) and the second inner tank (2) communicate; a first heating tube (31) for heating the water stored in the first inner tank (1); a second heating tube (32) for heating the water stored in the second inner tank (2); a third heating tube (33) for heating the water stored in the second inner tank (2); a first temperature sensor (41) for detecting the temperature of the water in the first inner tank (1); a second temperature sensor (42) for detecting the temperature of the water in the second inner tank (2); a flow sensor (5) connected to the water inlet pipe (11) and / or the water outlet pipe (21) for detecting the flow of the water passing through the first inner tank (1) and the second inner tank (2); and a controller (6) electrically connected to the first heating tube (31), the second heating tube (32) and the third heating tube (33) to control the start or stop of the first heating tube (31), the second heating tube (32) and the third heating tube (33), and the controller (6) is also connected to the first temperature sensor (41), the second temperature sensor (42) and the flow sensor (5); the power of the first heating tube (31) is P1, the power of the second heating tube (32) is P2, and the power of the third heating tube (33) is P3, wherein: P1+P2=P2+P3, and P1>P2; characterized in that the heating control method comprises the following control steps: Step S1, initial water filling and power on: after cold water fills the first inner tank (1) and the second inner tank (2), the power is started, the controller (6) controls the first heating tube (31) to start, the second heating tube (32) to start, and the third heating tube (33) to stop, the controller (6) receives the temperature T1i measured by the first temperature sensor (41) at the current time and the temperature T2i measured by the second temperature sensor (42) at the current time, and when T1i and T2i are equal to a set value T1, the controller (6) controls the first heating tube (31), the second heating tube (32) and the third heating tube (33) to stop working; Step S2, the controller (6) receives the flow Qi measured by the flow sensor (5) at the current time, and judges the size relationship between Qi and a set value Q1; if Qi≥Q1, then Step S3 is entered; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ If 0 < Qi < Q1, judge the size relationship between the current time T1i, T2i and the set value T1; If T1i = T2i = T1, return to step S2; If T1i < T1 or T2i < T1, enter step S3; Step S3, the controller (6) controls the first heating tube (31) to start, the second heating tube (32) to start, and the third heating tube (33) to stop, and judges the size relationship between the current time T1i, T2i and the set value T1 and the set value T2; If T1i = T2i = T1, the controller (6) controls the first heating tube (31), the second heating tube (32) and the third heating tube (33) to stop working, and returns to step S2; If T2 ≤ T2i < T1, return to step S3; If T2i < T2, enter step S4; Step S4, the controller (6) controls the first heating tube (31) to stop, the second heating tube (32) to start, and the third heating tube (33) to start, and judges the size relationship between the current time T2i and the set value T1 and the set value T2; If T2i < T2, return to step S4; If T2 ≤ T2i < T1, return to step S3.

2. The heating control method of a dual-tank water heater according to claim 1, wherein The range of T1 is 40℃-80℃.

3. The heating control method of a dual-tank water heater according to claim 1, wherein T2 = T1-Tk, wherein the value of Tk is 5℃-8℃.

4. The heating control method of a dual-tank water heater according to claim 1, wherein 0.9L / min ≤ Q1 ≤ 1.1L / min.

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