CN112648726A - Water heater and detection method for input water flow of water heater - Google Patents

Abstract

The invention provides a water heater and a method for detecting input water flow of the water heater, wherein the water heater comprises: a housing; the water inlet pipe is arranged on the shell; the heating structure is arranged in the water inlet pipe; the first temperature detection structure and the second temperature detection structure are arranged in the water inlet pipe and are respectively positioned at the upstream position and the downstream position of the heating structure; and the heating structure, the first temperature detection structure and the second temperature detection structure are all connected with the control device. The technical scheme of the invention overcomes the defect that the flow detection structure of the water heater in the prior art is easily affected by water scale.

Description

Water heater and detection method for input water flow of water heater

Technical Field

The invention relates to the technical field of hot water equipment, in particular to a water heater and a detection method of input water flow of the water heater.

Background

In the existing gas water heater products, a special paddle wheel flowmeter is needed to realize the detection of input water flow. The principle of the device is that a magnet is embedded in the edge of a paddle wheel, the paddle wheel drives the magnet to rotate under the impact of water flow, the rotating speed of the magnet is detected through a Hall element, and the instantaneous flow rate is obtained, namely the flow rate per pulse, the pulse number per time. However, the above technical solutions have the following disadvantages: the flow sensor is susceptible to scale, and if too many layers of scale are deposited, the flow channel in the pipeline may become narrow and restrict the flow, and the scale may adhere to the inside of the flowmeter, thereby adversely affecting the normal operation of the flowmeter.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect that the flow detection structure of the water heater in the prior art is easily affected by scale, so that the water heater and the detection method of the input water flow of the water heater are provided.

In order to solve the above technical problem, the present invention provides a water heater, comprising: a housing; the water inlet pipe is arranged on the shell; the heating structure is arranged in the water inlet pipe; the first temperature detection structure and the second temperature detection structure are arranged in the water inlet pipe and are respectively positioned at the upstream position and the downstream position of the heating structure; and the heating structure, the first temperature detection structure and the second temperature detection structure are all connected with the control device.

Optionally, the first temperature detecting structure and the second temperature detecting structure are thermocouples.

Optionally, the positive electrode of the first temperature detection structure is connected with the positive electrode of the second temperature detection structure, the negative electrode of the first temperature detection structure is connected with the negative electrode of the second temperature detection structure to form a loop, and the control device includes a detection device for detecting a voltage value of the loop.

Optionally, the thermocouple is a T-type thermocouple, a K-type thermocouple, or an E-type thermocouple.

Optionally, the first temperature detecting structure and the second temperature detecting structure are NTC resistors or platinum resistors.

The invention also provides a method for detecting the input water flow of the water heater, wherein the water heater is the water heater, and the control method comprises the following steps: step S1: obtaining a temperature difference value of temperature values detected by the first temperature detection structure and the second temperature detection structure; step S2: obtaining the quality of input water in the water inlet pipe according to the temperature difference; step S3: and obtaining the input water flow of the water inlet pipe according to the quality of the input water.

Alternatively, in step S2, the mass of the input water is obtained by the following formula: equation 1: q1 ═ C × M Δ T; wherein Q1 is the heat of the water absorbing heating structure, C is the specific heat capacity of water, M is the mass of input water, and Δ T is the temperature difference.

Alternatively, in equation 1, Q1 is obtained by the following equation: equation 2: q1 ═ k × Q2; wherein Q1 is the heat of the water absorbing heating structure, k is the heat absorption coefficient, and Q2 is the heat emitted by the heating structure.

Optionally, the water heater is the water heater of claim 3, and in equation 1, Δ T is obtained by the following equation: equation 3: vout α ab Δ T; vout is the thermoelectromotive force in the loop, α ab is the Seebeck coefficient of the thermocouple, and Δ T is the temperature difference.

Alternatively, in step S3, the input water flow rate is obtained by the following formula: equation 4:

wherein Q is input water flow, M is input water quality, and t is heating time of the heating structure.

The technical scheme of the invention has the following advantages:

by adopting the technical scheme of the invention, the first temperature detection structure and the second temperature detection structure can measure the temperature change of water after passing through the heating structure, and the control device calculates the input water flow of the water inlet pipe according to the heating parameters of the heating structure and the difference value of the temperature change according to the heat absorption formula. The structure calculates the flow of input water by measuring the temperature, so that the influence of scales is avoided, and the measurement result is stable. Therefore, the technical scheme of the invention overcomes the defect that the flow detection structure of the water heater in the prior art is easily affected by water scale.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 shows a schematic of the construction of the water heater of the present invention;

FIG. 2 is a schematic connection diagram illustrating a first temperature sensing structure, a second temperature sensing structure and a heat generating structure of the water heater of FIG. 1;

fig. 3 is a schematic view illustrating a connection of a first temperature sensing structure and a second temperature sensing structure of the water heater of fig. 1.

Description of reference numerals:

10. a housing; 20. a water inlet pipe; 30. a heat generating structure; 40. a first temperature detection structure; 50. a second temperature detection structure; 60. a control device; 61. and (4) a detection device.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1 and 2, the water heater in the present embodiment includes a housing 10, a water inlet pipe 20, a heat generating structure 30, a first temperature detecting structure 40, and a second temperature detecting structure 50. Wherein the water inlet pipe 20 is provided on the housing 10. The heat generating structure 30 is disposed within the water inlet pipe 20. The first and second temperature detecting structures 40 and 50 are disposed in the water inlet pipe 20, and the first and second temperature detecting structures 40 and 50 are located at upstream and downstream positions of the heat generating structure 30, respectively. The control device 60, the heat generating structure 30, the first temperature detecting structure 40 and the second temperature detecting structure 50 are all connected with the control device 60.

With the technical solution of this embodiment, the first temperature detecting structure 40 and the second temperature detecting structure 50 can measure the temperature change of water after passing through the heating structure 30, and according to the heat absorption formula, the control device 60 calculates the input water flow rate of the water inlet pipe 20 according to the heating parameters of the heating structure 30 and the difference value of the temperature changes. The structure calculates the flow of input water by measuring the temperature, so that the influence of scales is avoided, and the measurement result is stable. Therefore, the technical scheme of the embodiment overcomes the defect that the flow detection structure of the water heater is easily affected by the scale in the prior art.

As shown in fig. 2, in the solution of the present embodiment, the first temperature detecting structure 40 and the second temperature detecting structure 50 are located upstream and downstream of the heat generating structure 30, which means located on both sides of the heat generating structure 30, respectively. As can be seen from fig. 2, the first temperature detecting structure 40 is located at a lower side of the heat generating structure 30, and the second temperature detecting structure 50 is located at an upper side of the heat generating structure 30. The temperatures measured by the two are the temperatures of water, which rises after passing through the heat generating structure 30, and thus the temperatures of water located upstream and downstream of the heat generating structure 30 are different, and the first temperature detecting structure 40 and the second temperature detecting structure 50 are used to measure the above-mentioned temperature difference. How to obtain the flow rate of the water input at the water inlet pipe 20 through the temperature difference detected by the first temperature detecting structure 40 and the second temperature detecting structure 50 will be described below, and the structure of the water heater will be described first:

as shown in fig. 1 and 2, in the solution of the present embodiment, the first temperature detecting structure 40 and the second temperature detecting structure 50 are thermocouples. Specifically, the working principle of the thermocouple is as follows: two different materials (metal or semiconductor) are connected to form a closed loop, and if the two contacts are kept at different temperatures TA and TB, electromotive force is generated in the loop, so that current flows in the loop. This electromotive force is called a thermoelectric electromotive force, and this phenomenon is called a seebeck effect. Experiments prove that the temperature difference electromotive force VOUT is related to the temperature of two joints and substances forming a closed loop.

Based on the above principle, as shown in fig. 2 and 3, the positive electrode of the first temperature detection structure 40 and the positive electrode of the second temperature detection structure 50 are connected together, the negative electrode of the first temperature detection structure 40 and the negative electrode of the second temperature detection structure 50 are connected together and form a loop, and the control device 60 includes a detection device 61 that detects a voltage value of the loop. Specifically, the positive electrode and the negative electrode of the thermocouple are made of different materials, and in the present embodiment, the first temperature detection structure 40 and the second temperature detection structure 50 are made of the same thermocouple, so that the positive electrode of the first temperature detection structure 40 is made of the same material as the positive electrode of the second temperature detection structure 50, and the negative electrode of the first temperature detection structure 40 is made of the same material as the negative electrode of the second temperature detection structure 50. Through the above connection manner, the positive and negative electrodes of the first temperature detection structure 40 and the positive and negative electrodes of the second temperature detection structure 50 are located in the same loop, and according to the above principle, a temperature difference exists between the first temperature detection structure 40 and the second temperature detection structure 50, which results in a thermoelectromotive force existing in the loop. As can also be seen from fig. 3, the detecting device 61 detects the voltage value between the first temperature detecting structure 40 and the second temperature detecting structure 50, i.e. the thermoelectromotive force in the loop. The voltage signals pass through the signal modulation circuit, the PGA circuit and the AD conversion circuit and then are calculated through the MCU, and finally the temperature difference value is obtained.

Preferably, the thermocouple is a T-type thermocouple, a K-type thermocouple or an E-type thermocouple. The above-described thermocouple is different in the materials of the positive electrode and the negative electrode. Preferably, in the present embodiment, the first temperature detecting structure 40 and the second temperature detecting structure 50 are T-type thermocouples, so that the positive electrode is copper and the negative electrode is nickel-copper alloy. The temperature measurable range of the T-type thermocouple is generally in the range of-200 to +350 ℃.

As can be seen from the above description, the input water flow rate of the water inlet pipe 20 can be obtained by actually obtaining the temperatures at both sides of the heat generating structure 30 upstream and downstream. Therefore, it will be understood by those skilled in the art that the first temperature detecting structure 40 and the second temperature detecting structure 50 may be other structures capable of detecting temperature, for example, the first temperature detecting structure and the second temperature detecting structure may also be NTC resistors or platinum resistors.

The above is the specific structure of the water heater in this embodiment, and the specific method for obtaining the input water flow rate of the water inlet pipe 20 will be described in detail below.

The embodiment also provides a method for detecting the input water flow of the water heater, wherein the water heater is the water heater, and the control method comprises the following steps:

step S1: obtaining a temperature difference value of temperature values detected by the first temperature detection structure 40 and the second temperature detection structure 50;

step S2: obtaining the quality of the input water in the water inlet pipe 20 according to the temperature difference;

step S3: the input water flow rate of the water inlet pipe 20 is obtained according to the input water quality.

First, in step S2, the mass of input water is obtained by the following formula:

equation 1: q1 ═ C × M Δ T;

where Q1 is the heat of the water absorbing heating structure 30, C is the specific heat capacity of water, M is the mass of the input water, and Δ T is the temperature difference.

Specifically, formula 1 is a heat absorption/emission formula, where Q is heat, C is specific heat capacity, and Δ T is a difference in temperature. Since the mass of the input water is required in this embodiment, the absorbed heat and the temperature difference are measured for the water accordingly. In the above formula 1, C is the specific heat capacity of water, which is a constant value, and how Q1 and Δ T are obtained is explained below.

In this embodiment, in equation 1, Q1 is obtained by the following equation:

equation 2: q1 ═ k × Q2;

wherein Q1 is the heat of the water absorbing heat generating structure 30, k is the heat absorption coefficient, and Q2 is the heat of the heat generating structure 30.

As described above, the temperature change of the water needs to be measured in equation 1, and the reason for the temperature change of the water is that the water absorbs heat after passing through the heat generating structure 30, so that the temperature of the water located downstream of the heat generating structure 30 is higher than the temperature of the water located upstream of the heat generating structure 30. In the second formula, the heat Q2 emitted from the heat generating structure 30 is available, and specifically, the heat generating structure 30 is connected to the control device 60, so that the control device 60 can obtain the heat generating power and the heat generating time of the heat generating structure 30.

Further, as can be understood by those skilled in the art, after the water passes through the heat generating structure 30, the water cannot absorb all of the heat generated by the heat generating structure 30, and thus, a correction is required. The endothermic coefficient k is thus introduced in equation 2. According to different structures of water inlet pipes 20 of different types of water heaters, the heat absorption coefficients k of water passing through the heating structure 30 are different, and the heat absorption coefficients k of different water heater products can be obtained through limited experiments without creative labor by a person skilled in the art.

In this embodiment, in formula 1, Δ T is obtained by the following formula:

equation 3: vout α ab Δ T;

vout is the thermoelectromotive force in the loop, α ab is the Seebeck coefficient of the thermocouple, and Δ T is the temperature difference.

Specifically, if the first temperature detection structure 40 and the second temperature detection structure 50 can accurately measure the upstream and downstream temperatures of the heat generating structure 30, Δ T can be obtained by subtracting the two values. Since the first temperature detecting structure 40 and the second temperature detecting structure 50 are thermocouples in this embodiment, the detecting device can detect the thermoelectromotive force Vout in the loop according to the above content, and the thermoelectromotive force Vout is directly proportional to the temperature difference Δ T in a range where the temperature difference is not large, so that the seebeck coefficient (seebeck coefficient) is a constant when the thermocouple models of the first temperature detecting structure 40 and the second temperature detecting structure 50 are determined, and the Δ T can be obtained by simple calculation of the detecting device 61.

In summary, combining the formula 1, the formula 2 and the formula 3, the quality of the input water of the water inlet pipe 20 can be obtained.

Further in the present embodiment, in step S3, the input water flow rate is obtained by the following formula: equation 4:

where Q is the input water flow, M is the input water mass, and t is the heating time of the heating structure 30.

Specifically, the flow rate of the input water is equal to the volume of the input water divided by the time, and the volume of the input water is equal to the mass of the input water divided by the density. Obviously, the medium passing through the inlet conduit 20 is water, the density of which is constant. The mass of the input water (i.e., M) in equation 4 has been obtained by equation 1. And as for the time t, those skilled in the art can understand that the mass of the input water in equation 1 is calculated based on the heat of the water absorbing heat generating structure 30, and thus the time for the input water to pass should be the heat generating time of the heat generating structure 30 when the input water flow rate is calculated in equation 4. As described above, the control device 60 may preset or store the heat generation time of the heat generating structure 30, and thus, in calculating equation 4, the control device may call the heat generation time parameter of the heat generating structure 30.

To sum up, according to the structure of the water heater itself to and through the heat formula, can obtain all parameters in formula 4, and then calculate the input water flow of water heater, consequently the technical scheme of this embodiment need not set up the flowmeter and also can obtain input water flow parameter, and then the measuring result can not receive the influence of incrustation scale for measuring result is more stable.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (10)

1. A water heater, comprising:

a housing (10);

a water inlet pipe (20) disposed on the housing (10);

the heating structure (30) is arranged in the water inlet pipe (20);

a first temperature detection structure (40) and a second temperature detection structure (50) disposed within the water inlet pipe (20), and the first temperature detection structure (40) and the second temperature detection structure (50) are respectively located at an upstream position and a downstream position of the heat generating structure (30);

the control device (60), the heating structure (30), the first temperature detection structure (40) and the second temperature detection structure (50) are all connected with the control device (60).

2. The water heater according to claim 1, wherein the first temperature detecting structure (40) and the second temperature detecting structure (50) are thermocouples.

3. A water heater according to claim 2, wherein the positive pole of the first temperature detecting structure (40) is connected with the positive pole of the second temperature detecting structure (50), the negative pole of the first temperature detecting structure (40) is connected with the negative pole of the second temperature detecting structure (50) and forms a loop, and the control device (60) comprises a detecting device (61) for detecting the voltage value of the loop.

4. The water heater of claim 2, wherein the thermocouple is a T-type thermocouple, a K-type thermocouple, or an E-type thermocouple.

5. The water heater according to claim 1, wherein the first and second temperature sensing structures are NTC resistors or platinum resistors.

6. A method for detecting input water flow of a water heater, wherein the water heater is the water heater of any one of claims 1 to 5, and the control method comprises the following steps:

step S1: obtaining a temperature difference value of temperature values detected by the first temperature detection structure (40) and the second temperature detection structure (50);

step S2: obtaining the quality of the input water in the water inlet pipe (20) according to the temperature difference;

step S3: and obtaining the input water flow of the water inlet pipe (20) according to the quality of the input water.

7. The method for detecting according to claim 6, wherein in the step S2, the mass of the input water is obtained by the following formula:

equation 1: q1 ═ C × M Δ T;

wherein Q1 is the heat of the heating structure (30) absorbed by water, C is the specific heat capacity of water, M is the mass of the input water, and Δ T is the temperature difference.

8. The detection method according to claim 7, wherein in the formula 1, the Q1 is obtained by the following formula:

equation 2: q1 ═ k × Q2;

wherein the Q1 is the heat of the heating structure (30) absorbed by water, the k is the heat absorption coefficient, and the Q2 is the heat emitted by the heating structure (30).

9. The method for detecting according to claim 7, wherein the water heater is the water heater of claim 3, and in the formula 1, the Δ T is obtained by the following formula:

equation 3: vout α ab Δ T;

wherein, the Vout is the thermoelectromotive force in the loop, the α ab is the Seebeck coefficient of the thermocouple, and the Δ T is the temperature difference.

10. The detection method according to claim 6, wherein in the step S3, the input water flow rate is obtained by the following formula:

equation 4:

wherein Q is the input water flow, M is the input water mass, and t is the heating time of the heating structure (30).

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