CN103060818A - Full-automatic control-corrosion system and application method of solar-energy hot-water storage tank - Google Patents

Abstract

The invention relates to the technical field of metal anticorrosion, in particular to a fully automatic corrosion control system for a solar hot water storage tank and a method for using the same. The system includes a current generating component (1), an auxiliary anode (8) and a cable (10), wherein the outer wall of the hot water storage tank (3) is provided with a cathode tank electrical connection terminal (9), and the inner wall is provided with an auxiliary anode (8), the cathode tank electrical connection terminal (9) and the auxiliary anode (8) are respectively electrically connected to the generating current component (1); one side of the generating current component (1) is provided with an integral control unit electrically connected thereto Circuit (2); the inner wall of the hot water storage tank is also provided with a liquid level sensor (4) and a temperature sensor (7) electrically connected to the integral control circuit (2). The invention has the advantages of simple structure, convenient use, low cost and convenient control, and can automatically adjust the output current according to the temperature and liquid level of the corrosive medium in the hot water storage tank, so that the hot water storage tank is in a protected state at any time.

Description

A fully automatic corrosion control system for solar hot water storage tanks and its application method

technical field

The invention relates to the technical field of metal anticorrosion, in particular to a fully automatic corrosion control system for a solar hot water storage tank and a method for using the same.

Background technique

Combine a large number of single sets of solar collectors to form a large-scale solar water heating system to provide collective hot water supply for hotels, hospitals, schools, guesthouses, and high-end residential areas. The solar hot water storage tank is used to store the hot water from the collector and the supplementary low-temperature tap water or ground water, which is an important part of the system. Although the corrosion of steel structures in the conventional fresh water environment is relatively light, the high temperature of the water medium in the storage tank reaches 80-90 °C, and the low temperature is 0-10 °C when the water is supplied. The long-term high and low temperature alternation in the tank accelerates the corrosion of the tank body; The salt content of the tank is high, the corrosion is strong, and the corrosion and perforation of the tank wall occur from time to time.

Corrosion protection techniques for hot water storage tanks include sacrificial anodes and impressed current methods. Due to the high temperature of the medium in the tank, the consumption of conventional aluminum and magnesium anodes is fast, and the protection time is short. Especially for large storage tanks of tens of tons, a large number of sacrificial anodes need to be installed, and the project cost is high. In addition, long-term drinking of water containing aluminum ions can easily lead to senile dementia; and the survey found that the dissolved products of magnesium anodes are flocculent, which is easy to block the lotus nozzle. In some areas, the water contains a lot of SO42-, S2-, these ions and magnesium, etc. The metal reacts to form H2S gas, which produces the smell of rotten eggs. Applied current method can be divided into constant potential method and constant current method. The constant potential method requires a stable electrode as a reference. By applying a certain protection current, the steel structure on the inner wall of the storage tank is polarized to the protection potential range. However, no stable potential that can be used in this high temperature environment for a long time has been found so far. the reference electrode. The constant current method is to provide a certain protection current to the tank to polarize it to the protection potential range. The key technology is to first determine the size of the protection current.

Contents of the invention

In order to solve the above technical problems, the object of the present invention is to provide a solar hot water storage system with simple structure, convenient use, low cost and convenient control, which can automatically adjust the output current according to the temperature and liquid level of the corrosive medium in the hot water storage tank. Fully automatic corrosion control system for tanks and method of use thereof.

In order to achieve the above purpose, the present invention provides a fully automatic corrosion control system for solar hot water storage tanks, which includes a current generating assembly 1, an auxiliary anode 8 and a cable 10, wherein the outer wall of the hot water storage tank 3 is provided with a cathode The tank electrical connection terminal 9, the inner wall of the hot water storage tank 3 is provided with an auxiliary anode 8, the cathode tank electrical connection terminal 9 and the auxiliary anode 8 are respectively electrically connected to the generating current component 1; one side of the generating current component 1 is provided There is an integral control circuit 2 electrically connected thereto; the inner wall of the hot water storage tank is also provided with a liquid level sensor 4 and a temperature sensor 7 electrically connected with the integral control circuit 2 .

The number of the auxiliary anodes 8 is two, one is fixedly arranged at the upper middle part of the inner wall of the hot water storage tank 3, the other is fixedly arranged at the middle and lower part of the inner wall of the hot water storage tank 3, and the two auxiliary anodes 8 are oppositely arranged.

The cathode tank electrical connection terminal 9 is electrically connected to the negative pole of the current generating component 1 through a cable 10 ; the auxiliary anode 8 is electrically connected to the positive pole of the current generating component 1 through the cable 10 .

The liquid level sensor 4 is located above the water outlet 5 of the hot water storage tank 3, the number of the liquid level sensors 4 is multiple, and the plurality of liquid level sensors 4 are equidistantly fixedly installed on the top of the hot water storage tank 3. inner wall.

The temperature sensor 7 is located above the water inlet 6 of the hot water storage tank 3 and is fixedly installed above the auxiliary anode 8 at the middle and lower part of the inner wall of the hot water storage tank 3 .

In order to better achieve the purpose of the present invention, the present invention further provides a method for using a fully automatic corrosion control system for solar hot water storage tanks, which includes the following steps:

a. The hot water storage tank 3 stores a medium with a certain temperature, connects the external power supply, and turns on the generating current component 1 and the integral control circuit 2;

b. The temperature sensor 7 automatically senses the temperature of the medium to test the protection current density of the hot water storage tank 3 in the medium temperature at different temperatures;

c. The liquid level sensor 4 automatically senses the liquid level of the medium to test the total area of the inner wall of the hot water storage tank 3 in contact with the medium when the liquid level is different;

d. The two groups of test result signals gained in the b and c steps are delivered to the integral control circuit 2;

e. Integral control circuit 2 automatically converts protection current according to medium liquid level height and medium temperature, and feeds it back to generating current component generating current component 1;

f. The current generating component 1 applies a certain current between the electrical connection terminal 9 of the cathode tank and the auxiliary anode 8 according to the instruction.

Among them, in step b: test the protection current density per unit area required by the hot water storage tank (3) at different temperatures in the storage medium, the approximate equivalent function relationship between temperature and unit area protection current is: I _t =a ₁ + b ₁ t, 0≤t≤85℃; where,

t is the temperature of the water in the tank, in °C;

a ₁ is a constant, and the size of a ₁ is equal to the protection current density required by the unit material when t is zero degrees Celsius;

b ₁ is a proportional constant, reflecting the relationship between the protection current density and the temperature change;

I _t is the electric current required for the complete protection of the metal material of the storage tank wall per unit area at different temperatures, unit: mA/cm ² .

In step c, when testing different liquid level heights, the total area of the inner wall of the hot water storage tank (3) in contact with the medium; the approximate equivalent functional relationship between the liquid level height and the total contact area is: S _h =a ₂ +b ₂ h, 0≤h; where,

h is the height of the liquid level in cm;

a ₂ is a constant, and the size of a ₂ is equal to the tank bottom area when h is zero;

_b2 is a proportional constant, which reflects the relationship between the contact area between the inner wall of the storage tank and the water with the height of the liquid level;

S _h is the total area of the inner wall of the storage tank in contact with the medium at different liquid level heights, the unit is cm ² .

In step e, the integral control current conversion formula is:

I _p =I _t ×S _h =(a ₁ +b ₁ t)×(S _h =a ₂ +b ₂ h)

Among them, I _p is the protection current required for complete protection of the inner wall of the storage tank at different temperatures and different liquid level heights.

The invention has the advantages of simple structure, convenient use, low cost and convenient control, and can automatically adjust the output current according to the temperature and liquid level of the corrosive medium in the hot water storage tank, so that the inner wall of the storage tank is always in a state of comprehensive corrosion control.

Description of drawings

Fig. 1 is a schematic diagram of the installation state of the fully automatic corrosion control system of the present invention.

[Description of main component symbols]

1 Generating current component

2 Integral control circuit

3 hot water storage tanks

4 Liquid level sensor

5 water outlet

6 water inlet

7 temperature sensor

8 auxiliary anode

9 Cathode tank electrical connection terminal

10 cables

Detailed ways

The specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings.

The automatic corrosion control system for solar hot water storage tanks of the present invention includes a current generating assembly 1, an auxiliary anode 8 and a cable 10, wherein the outer wall of the hot water storage tank 3 is provided with a cathode tank electrical connection terminal 9, and the hot water storage tank The inner wall of 3 is provided with an auxiliary anode 8, and the cathode tank electrical connection terminal 9 is electrically connected to the negative pole of the current generating component 1 through a cable 10; the auxiliary anode 8 is electrically connected to the positive pole of the current generating component 1 through the cable 10; One side of the current component 1 is further provided with an integral control circuit 2 , and the current generating component 1 and the integral control circuit 2 are electrically connected through a cable 10 .

In this embodiment, the number of auxiliary anodes 8 is two, one is fixedly arranged at the middle and upper part of the inner wall of the hot water storage tank 3, and the other is fixedly arranged at the middle and lower part of the inner wall of the hot water storage tank 3, and the two auxiliary anodes 8 face each other. set up.

The inner wall of the hot water storage tank is also provided with a liquid level sensor 4 and a temperature sensor 7, wherein the liquid level sensor 4 is located above the water outlet 5 of the hot water storage tank 3, and the number of the liquid level sensors 4 is as many as A plurality of liquid level sensors 4 are equidistantly fixedly installed on the inner wall of the hot water storage tank 3, and the plurality of liquid level sensors 4 are electrically connected with the integral control circuit 2 through a cable 10; the temperature sensor 7 is located in the hot water The top of the water inlet 6 of the storage tank 3 is fixedly installed above the auxiliary anode 8 in the middle and lower part of the inner wall of the hot water storage tank 3 , and the temperature sensor 7 is electrically connected with the integral control circuit 2 through a cable 10 .

Wherein, the current generation component 1 is a transformer rectifier for converting 220V household AC power into low-voltage direct current and can adjust the output current. The input terminal of the generating current component 1 is household 220V AC (low-voltage DC power supply can also be used to replace it if necessary), and the output positive pole is connected to the auxiliary anode 8 (usually a metal oxide anode. In order to make the current distribution of the tank body uniform, it can Install multiple auxiliary anodes at the same time), and the negative electrode is connected to the tank.

The integral control circuit 2 is mainly used in occasions such as waveform transformation, elimination of offset voltage of amplifying circuit, and integral compensation in feedback control.

The working principle of the automatic corrosion control system for solar hot water storage tanks of the present invention is to test and determine the units of storage tank steel at different temperatures in tap water (or other water sources, which are assumed to be tap water in this application) stored in the laboratory. The protective current density required by the area, the temperature and the protective current per unit area are approximately equivalent to a functional relationship; when calculating the total area of the tank inner wall in contact with tap water at different liquid level heights, the liquid level height and the water receiving area can also be approximated as A functional relationship. The above two approximate functions are programmed and stored in the integral control circuit 2, so far only the temperature of the medium in the tank and the height of the liquid level need to be known, and the integral control circuit 2 will automatically calculate the required protection current according to the water temperature and liquid level , and feed back to the generating current component 1 at the same time; specifically:

The temperature and liquid level transmission height sensor transmits the temperature and liquid level parameters of the tap water in the storage tank to the integral control circuit, and the integral control circuit calculates the protection current signal to be applied through internal logic operations, and transmits the signal to the generating current component , the generating current component applies a certain protection current to the tank through the auxiliary anode to make it polarized to the protection potential range.

Therefore, the method for using the automatic corrosion control system for solar hot water storage tanks of the present invention comprises the following steps:

a. The hot water storage tank 3 stores a medium with a certain temperature, connects the external power supply, and turns on the generating current component 1 and the integral control circuit 2;

b. The temperature sensor 7 automatically senses the temperature of the medium to test the protection current density of the hot water storage tank 3 in the medium temperature at different temperatures;

c. The liquid level sensor 4 automatically senses the liquid level of the medium to test the total area of the inner wall of the hot water storage tank 3 in contact with the medium when the liquid level is different;

d. The two groups of test result signals gained in the b and c steps are delivered to the integral control circuit 2;

e. Integral control circuit 2 automatically converts protection current according to medium liquid level height and medium temperature, and feeds it back to generating current component generating current component 1;

f. The current generating component 1 applies a certain current between the electrical connection terminal 9 of the cathode tank and the auxiliary anode 8 according to the instruction.

In the above step b: the protection current density per unit area required by the hot water storage tank at different temperatures in the stored tap water, the temperature and the protection current per unit area are approximately equivalent to a functional relationship, and the specific function is: I _t = a ₁ +b ₁ t, 0≤t≤85℃.

Among them, I _t is the current required by the metal material of the tank wall per unit area to achieve complete protection at different temperatures, and the unit is: mA/cm ² .

a ₁ and b ₁ are constants, and the size of a ₁ is equal to the protection current density required by the unit material when t is zero. b ₁ is a proportionality constant, which reflects the relationship between the protection current density and the temperature change. t is the temperature of the water in the tank, in °C.

In step c, calculate the contact area between the inner wall of the storage tank and water at different liquid level heights. The liquid level height and the total contact area are approximately equivalent to a functional relationship, and the specific function is: S _h =a ₂ +b ₂ h, 0≤ h.

Among them, S _h is the contact area between the inner wall of the storage tank and water at different liquid level heights, the unit is cm ² ,

a ₂ and b ₂ are constants, and a ₂ is equal to the tank bottom area when h is zero. b ₂ is a proportional constant, which reflects the relationship between the contact area between the inner wall of the storage tank and the water with the height of the liquid level. h is the height of the liquid surface in cm.

In step e, the integral control current conversion formula is: I _p =I _t ×S _h =(a ₁ +b ₁ t)×(S _h =a ₂ +b ₂ h)

Among them, I _p is the protection current required for complete protection of the inner wall of the storage tank at different temperatures and different liquid level heights.

When the solar hot water storage tank automatic corrosion control system of the present invention works: first, connect the external power supply, open the generating current assembly 1 and the integral control circuit 2, the hot water storage tank 3 stores a medium with a certain temperature, and the temperature sensor 7 The liquid level sensor 4 automatically senses the water temperature and liquid level height, and transmits the signal instruction to the integral control circuit 2, and the integral control circuit 2 feeds back the signal to the generating current component 1 after conversion, and the generating current component 1 generates electricity in the cathode tank according to the instruction. A certain current is applied to the connecting terminal 9 and the auxiliary anode 8 to polarize the potential of the hot water storage tank to the protection potential range, so as to achieve the effect of corrosion control.

Claims (9)

1. The utility model provides a full-automatic corrosion control system of solar water heating storage tank, it is including taking place electric current subassembly (1), supplementary positive pole (8) and cable conductor (10), its characterized in that:

the outer wall of the hot water storage tank (3) is provided with a cathode tank body electric connecting terminal (9), the inner wall of the hot water storage tank (3) is provided with an auxiliary anode (8), and the cathode tank body electric connecting terminal (9) and the auxiliary anode (8) are respectively and electrically connected with the current generation assembly (1); an integral control circuit (2) electrically connected with the current generating assembly (1) is arranged on one side of the current generating assembly; the inner wall of the hot water storage tank is also provided with a liquid level sensor (4) and a temperature sensor (7) which are electrically connected with the integral control circuit (2).

2. The full-automatic corrosion control system of claim 1, characterized in that: the number of the auxiliary anodes (8) is two, one auxiliary anode is fixedly arranged at the middle upper part of the inner wall of the hot water storage tank (3), the other auxiliary anode is fixedly arranged at the middle lower part of the inner wall of the hot water storage tank (3), and the two auxiliary anodes (8) are oppositely arranged.

3. The full-automatic corrosion control system of claim 1, characterized in that: the cathode tank electrical connection terminal (9) is electrically connected with the negative electrode of the current generation assembly (1) through a cable (10); and the auxiliary anode (8) is electrically connected with the anode of the current generation assembly (1) through a cable (10).

4. The full-automatic corrosion control system of claim 1, characterized in that: liquid level sensor (4) are located the top of delivery port (5) of hot water storage tank (3), and the figure of liquid level sensor (4) is a plurality of, the fixed mounting of a plurality of liquid level sensor (4) equidistance in the inner wall of hot water storage tank (3).

5. The full-automatic corrosion control system of claim 1, characterized in that: the temperature sensor (7) is positioned above a water inlet (6) of the hot water storage tank (3) and is fixedly arranged above an auxiliary anode (8) at the middle lower part of the inner wall of the hot water storage tank (3).

6. A use method of a full-automatic corrosion control system of a solar hot water storage tank is characterized by comprising the following steps:

a. a medium with a certain temperature is stored in the hot water storage tank (3), an external power supply is connected, and the current generation assembly (1) and the integral control circuit (2) are turned on;

b. the temperature sensor (7) automatically senses the medium temperature so as to test the protection current density of the hot water storage tank (3) in the medium temperature at different temperatures;

c. the liquid level sensor (4) automatically senses the liquid level of the medium so as to test the total contact area of the inner wall of the hot water storage tank (3) and the medium when different liquid levels are tested;

d. transmitting two groups of test result signals obtained in the steps b and c to an integral control circuit (2);

e. the integral control circuit (2) automatically converts the liquid level height of the medium and the temperature of the medium into protection current and feeds the protection current back to the current generation component (1);

f. the current generating assembly (1) applies a certain current between the cathode can electrical connection terminal (9) and the auxiliary anode (8) according to the command.

7. The method for using the full-automatic corrosion control system for the solar hot water storage tank of claim 6, wherein the method comprises the following steps:

in the step b: the protection current density required by the unit area of the hot water storage tank (3) under different temperatures in the storage medium is tested, and the approximate equivalent function relationship between the temperature and the protection current in the unit area is as follows: i is_t=a₁+b₁t is not less than 0 and not more than 85 ℃; wherein,

t is the temperature of the water in the tank, and the unit is;

a₁is a constant number, a₁The protection current density required by the unit material when t is zero DEG C;

b₁is a proportionality constant which reflects the relation of the protection current density along with the temperature change;

I_tthe unit is that the unit area storage tank wall metal material reaches the required electric current of complete protection under different temperatures, unit: mA/cm²。

8. The use method of the full-automatic corrosion control system for the solar hot water storage tank according to claim 6, is characterized in that:

in the step c, testing the total contact area of the inner wall of the hot water storage tank (3) and the medium when different liquid level heights are tested; the liquid level height and the total contact area approximate equivalent function relation is as follows: s_h=a₂+b₂h, 0 is less than or equal to h; wherein,

h is the height of the liquid level, and the unit is cm;

a₂is a constant number, a₂The size is equal to the area of the bottom of the storage tank when h is zero;

b₂the water level is a proportionality constant and reflects the change relation between the contact area of the inner wall of the storage tank and water along with the height of the liquid level;

S_hthe total contact area of the inner wall of the storage tank and the medium under different liquid level heights is expressed in cm²。

9. The use method of the full-automatic corrosion control system for the solar hot water storage tank according to claim 6, is characterized in that:

in step e, the conversion formula of the integral control current is as follows:

I_p=I_t×S_h=(a₁+b₁t)×(S_h＝a₂+b₂h)

wherein I_pThe protection current required for completely protecting the inner wall of the storage tank under different temperatures and different liquid level heights is achieved.

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